\nNa\u2083AlF\u2086<\/td>\n 0<\/td>\n 0 – 5<\/td>\n 0 – 8<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\nMelting point of flux mixture:<\/strong><\/p>\nThe target melting point for a cover flux intended for aluminium is 550-650\u00b0C \u2014 well below the aluminium liquidus of 660\u00b0C. This ensures that the flux melts and flows into a continuous layer before the aluminium metal temperature rises to full processing temperature. A flux that melts above the aluminium processing temperature will not spread effectively and will leave unprotected areas of melt surface.<\/p>\n
Types of Aluminium Fluxes and How Cover Flux Differs from Cleaning and Refining Flux<\/h2>\nUnderstanding the Full Aluminium Flux Family<\/h3>\n The term “aluminium flux” is used loosely in the foundry industry to refer to several chemically and functionally distinct products. Purchasing the wrong flux type for your application is a common and costly mistake.<\/p>\n
Cover flux (protective flux):<\/strong>Cleaning flux (drossing flux):<\/strong>Refining flux:<\/strong>Degassing flux (tablet or powder):<\/strong>Grain refining flux:<\/strong>Flux function comparison table:<\/strong><\/p>\n\n
\n\n\nFlux Type<\/th>\n Application Timing<\/th>\n Application Method<\/th>\n Primary Benefit<\/th>\n Fluoride Level<\/th>\n<\/tr>\n<\/thead>\n \n\nCover flux<\/td>\n Continuous \/ frequent<\/td>\n Surface spreading<\/td>\n Oxidation prevention<\/td>\n Low to moderate<\/td>\n<\/tr>\n \nCleaning flux<\/td>\n Periodic (per heat or campaign)<\/td>\n Stirred into melt<\/td>\n Dross removal, cleanliness<\/td>\n Moderate to high<\/td>\n<\/tr>\n \nRefining flux<\/td>\n Corrective, as needed<\/td>\n Stirred into melt<\/td>\n Composition adjustment<\/td>\n Variable<\/td>\n<\/tr>\n \nDegassing flux<\/td>\n Per heat, before casting<\/td>\n Submerged tablet\/plunger<\/td>\n Hydrogen removal<\/td>\n Low<\/td>\n<\/tr>\n \nGrain refining flux<\/td>\n Per heat, timed addition<\/td>\n Wire or plunger addition<\/td>\n Grain structure refinement<\/td>\n High<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\nIn practice, a well-run aluminium foundry uses cover flux throughout the melting and holding period and supplements with periodic cleaning flux treatment before skimming. Degassing is typically handled by a rotary unit rather than flux tablets in modern operations. Understanding this distinction is critical when comparing prices between flux types \u2014 a supplier quoting a low price for a cleaning flux that is being requested as a cover flux will create operational problems.<\/p>\nHOW ALUMINUM DROSSING FLUX WORKS: REDUCING METAL LOSS & IMPROVING MELT QUALITY<\/figcaption><\/figure>\nHow Cover Flux Works: Physical Barrier vs. Chemical Protection Mechanisms<\/h2>\nThe Two Layers of Protection That Cover Flux Provides<\/h3>\n Cover flux protects liquid aluminium through two mechanisms operating simultaneously, and the relative contribution of each mechanism depends on the flux composition, application rate, and operating conditions.<\/p>\n
Mechanism 1: Physical barrier protection<\/strong><\/p>\nWhen cover flux is applied to the melt surface and melts to form a continuous molten salt layer, it physically separates the liquid aluminium from the furnace atmosphere. Oxygen, nitrogen, water vapour, and combustion products from gas burners cannot reach the aluminium surface through a continuous flux layer. This is the simplest and most intuitive protection mechanism.<\/p>\n
The effectiveness of physical barrier protection depends entirely on coverage continuity. A flux layer with gaps \u2014 caused by insufficient dosage, localised evaporation of low-boiling components, or mechanical disruption from stirring \u2014 provides proportionally less protection. The barrier must cover the entire melt surface continuously, including corners and edges where oxidation often concentrates.<\/p>\n
The flux layer also acts as a thermal insulator between the melt and the furnace atmosphere, reducing the temperature gradient at the melt surface and thereby slowing natural convection currents that would otherwise continuously expose fresh aluminium to the atmosphere.<\/p>\n
Mechanism 2: Chemical oxide dissolution and absorption<\/strong><\/p>\nThe fluoride components in cover flux actively react with aluminium oxide inclusions that form at the flux-metal interface:<\/p>\n
Al\u2082O\u2083 + 6NaF \u2192 2AlF\u2083 + 3Na\u2082O
These reactions dissolve Al\u2082O\u2083 into the flux phase, preventing the accumulation of a coherent oxide layer at the interface that would otherwise trap metal droplets and form dross. By continuously dissolving nascent oxide as it forms, a fluoride-containing cover flux keeps the melt-flux interface clean and maintains good contact between the protective salt layer and the fresh aluminium surface.<\/p>\n
This chemical dissolution mechanism is why fluoride-free or very-low-fluoride cover fluxes \u2014 despite providing physical barrier protection \u2014 are less effective at controlling dross formation than properly formulated fluoride-containing fluxes. The physical barrier alone prevents oxygen from reaching the melt, but it does not address the oxide that forms from oxygen absorbed before the flux layer is established, or from oxide films introduced with scrap charges.<\/p>\n
Protection efficiency by mechanism:<\/strong><\/p>\n\n
\n\n\nOperating Condition<\/th>\n Physical Barrier Contribution<\/th>\n Chemical Dissolution Contribution<\/th>\n Combined Protection<\/th>\n<\/tr>\n<\/thead>\n \n\nClean melt, no scrap charging<\/td>\n 70%<\/td>\n 30%<\/td>\n Excellent<\/td>\n<\/tr>\n \nActive scrap charging<\/td>\n 45%<\/td>\n 55%<\/td>\n Good<\/td>\n<\/tr>\n \nHigh-humidity environment<\/td>\n 50%<\/td>\n 50%<\/td>\n Good<\/td>\n<\/tr>\n \nHigh-magnesium alloy<\/td>\n 30%<\/td>\n 70%<\/td>\n Moderate (requires high-Mg formulation)<\/td>\n<\/tr>\n \nTurbulent melt (stirring)<\/td>\n 35%<\/td>\n 65%<\/td>\n Moderate (requires higher dosage)<\/td>\n<\/tr>\n \nLong holding periods<\/td>\n 65%<\/td>\n 35%<\/td>\n Good<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\nCover Flux Application Methods: Powder, Granule, and Tablet Forms Compared<\/h2>\nWhich Physical Form of Cover Flux Is Best for Your Operation?<\/h3>\n Cover flux is commercially available in three physical forms \u2014 powder, granule, and pressed tablet \u2014 each with distinct advantages and limitations that affect both performance and ease of application.<\/p>\nCover Flux application methods comparison showing powder, granule, and tablet forms with their advantages, applications, and industrial uses for molten metal processing.<\/figcaption><\/figure>\nPowder form (particle size 0.1 – 1.0 mm):<\/strong><\/p>\nPowdered cover flux spreads most easily over the melt surface and melts fastest to form a continuous layer due to its high surface-area-to-volume ratio. It can be applied manually using a sieve or shovel, or through automated pneumatic dispensing systems. The disadvantages of powder are significant: dust generation during handling creates respiratory hazards and flux losses before the material even reaches the melt; powder can be easily blown by furnace drafts before it melts into place; and storage requires careful moisture protection since the hygroscopic salts absorb atmospheric humidity readily.<\/p>\n
Granule form (particle size 1.0 – 5.0 mm):<\/strong><\/p>\nGranular cover flux represents the best balance of performance and handling practicality for most foundry environments. The larger particle size reduces dust generation during handling while still providing rapid melting and spreading on the melt surface. Granules are less susceptible to wind displacement before melting and flow freely from standard scoops and dispensing equipment. This is the form we most frequently recommend for manual application in foundry operations.<\/p>\n
Pressed tablet form (20 – 100g per tablet):<\/strong><\/p>\nTablets are produced by compressing powdered flux under high pressure without binders. They offer the cleanest handling characteristics \u2014 minimal dust, no spillage, easy counting for precise dosage control \u2014 and are well suited to automated addition systems where tablets are dropped onto the melt surface at controlled intervals. The tradeoff is slower initial melting compared to powder or granule due to the lower surface area, which can leave the melt surface partially unprotected during the melt-in period if tablets are placed infrequently. Tablets are commonly used in holding furnaces where the melt surface is stable and infrequent additions are acceptable.<\/p>\n
Physical form comparison:<\/strong><\/p>\n\n
\n\n\nProperty<\/th>\n Powder<\/th>\n Granule<\/th>\n Tablet<\/th>\n<\/tr>\n<\/thead>\n \n\nMelting speed<\/td>\n Fast<\/td>\n Moderate<\/td>\n Slow<\/td>\n<\/tr>\n \nDust generation<\/td>\n High<\/td>\n Low<\/td>\n Very low<\/td>\n<\/tr>\n \nHandling safety<\/td>\n Requires PPE<\/td>\n Standard PPE<\/td>\n Easy<\/td>\n<\/tr>\n \nDosage precision<\/td>\n Low<\/td>\n Moderate<\/td>\n High<\/td>\n<\/tr>\n \nMoisture sensitivity<\/td>\n Very high<\/td>\n High<\/td>\n Moderate<\/td>\n<\/tr>\n \nAutomated application<\/td>\n Possible (pneumatic)<\/td>\n Possible<\/td>\n Excellent<\/td>\n<\/tr>\n \nCoverage uniformity<\/td>\n Excellent<\/td>\n Good<\/td>\n Moderate<\/td>\n<\/tr>\n \nStorage requirement<\/td>\n Sealed, dry<\/td>\n Sealed, dry<\/td>\n Sealed, dry<\/td>\n<\/tr>\n \nBest application<\/td>\n Static furnaces, automated<\/td>\n Manual foundry use<\/td>\n Holding furnaces, automation<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\nApplication Equipment for Cover Flux<\/h3>\n Manual application uses simple handheld sieves or perforated scoops that allow even distribution over the melt surface. The operator should apply flux from the furnace door or charging area, distributing it across the entire melt surface including corners and edges \u2014 not simply dumping it in a pile at one location.<\/p>\n
Automated flux addition systems use either pneumatic conveying (for powder and fine granule) or mechanical feeders (for granule and tablet) to deliver controlled quantities of flux to the melt surface at preset intervals. These systems reduce labour cost, improve dosage consistency, and reduce dust exposure for furnace operators. They are cost-effective for operations running multiple shifts or where high flux consumption makes manual dosing labour-intensive.<\/p>\nCovering and Refining Flux for Aluminum Holding Furnaces<\/figcaption><\/figure>\nDosage Rates and Application Frequency by Furnace Type<\/h2>\nHow Much Cover Flux Should You Apply and How Often?<\/h3>\n Dosage rate is the most frequently misapplied aspect of cover flux use. Underdosing leaves areas of the melt surface unprotected and fails to suppress dross formation. Overdosing wastes flux, increases dross volume (the excess flux becomes part of the dross layer), and can introduce excess fluoride into the melt if the flux is excessively stirred.<\/p>\n
The correct dosage targets a continuous, self-levelling layer 5-15mm thick across the entire melt surface. This layer should appear smooth and molten at operating temperature, with no dry, unmelted patches, and no large accumulations that have become thick, viscous, and difficult to skim.<\/p>\n
Recommended cover flux dosage rates:<\/strong><\/p>\n\n
\n\n\nFurnace Type<\/th>\n Initial Charge Dosage (kg\/tonne Al)<\/th>\n Maintenance Dosage (kg\/tonne Al per hour)<\/th>\n Application Frequency<\/th>\n<\/tr>\n<\/thead>\n \n\nGas-fired reverberatory<\/td>\n 2.0 – 4.0<\/td>\n 0.5 – 1.5<\/td>\n Every 30-60 minutes<\/td>\n<\/tr>\n \nElectric resistance furnace<\/td>\n 1.0 – 2.5<\/td>\n 0.3 – 0.8<\/td>\n Every 60-90 minutes<\/td>\n<\/tr>\n \nInduction furnace (coreless)<\/td>\n 1.5 – 3.0<\/td>\n 0.4 – 1.0<\/td>\n Every 45-75 minutes<\/td>\n<\/tr>\n \nCrucible furnace (gas)<\/td>\n 1.5 – 3.0<\/td>\n 0.5 – 1.2<\/td>\n Every 30-60 minutes<\/td>\n<\/tr>\n \nHolding furnace<\/td>\n 0.5 – 1.5<\/td>\n 0.2 – 0.5<\/td>\n Every 60-120 minutes<\/td>\n<\/tr>\n \nLadle (transfer, short duration)<\/td>\n 1.0 – 2.0<\/td>\n N\/A<\/td>\n At start of transfer<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\nFactors that increase required dosage:<\/strong><\/p>\n\nHigh-humidity foundry environment (more moisture to exclude)<\/li>\n High-magnesium alloy composition (faster oxidation rate)<\/li>\n Elevated melt temperature (above 750\u00b0C)<\/li>\n Frequent scrap charging that disrupts the flux layer.<\/li>\n Burner flame impingement on melt surface (combustion gases attack flux layer)<\/li>\n Long holding times between casting operations.<\/li>\n<\/ul>\nFactors that allow reduced dosage:<\/strong><\/p>\n\nElectric furnace (no combustion atmosphere over the melt)<\/li>\n Low-humidity environment or air-conditioned facility<\/li>\n Inert atmosphere furnace (argon or nitrogen blanket over melt)<\/li>\n Clean, dry scrap charges requiring minimal melt-in.<\/li>\n Short holding times between ladle fillings.<\/li>\n<\/ul>\nIndustrial infographic illustrating the covering and refining functions of aluminum flux, including oxidation protection, impurity removal, degassing, and improved metal purity.<\/figcaption><\/figure>\nCover Flux Selection by Alloy Type: Why One Formula Does Not Suit All Alloys<\/h2>\nMatching Cover Flux Chemistry to Aluminium Alloy Composition<\/h3>\n The oxidation behaviour of aluminium changes significantly with alloy composition, and a cover flux formulation optimised for pure aluminium or low-alloy material may perform poorly on high-magnesium or high-zinc alloys. This is an area where we see significant losses in foundry operations that use a single flux formulation across their entire alloy range.<\/p>\n
Pure aluminium and 1xxx series:<\/strong>2xxx series (Al-Cu alloys):<\/strong>3xxx series (Al-Mn alloys):<\/strong>4xxx series (Al-Si alloys, including casting alloys A356, A380, A413):<\/strong>5xxx series (Al-Mg alloys, 2-6% Mg):<\/strong>6xxx series (Al-Mg-Si alloys, 0.2-1.2% Mg):<\/strong>7xxx series (Al-Zn-Mg alloys, up to 3% Mg):<\/strong>Flux formulation recommendation by alloy family:<\/strong><\/p>\n\n
\n\n\nAlloy Series<\/th>\n Mg Content (%)<\/th>\n Recommended Flux Type<\/th>\n Total Fluoride Target (%)<\/th>\n Dosage Adjustment vs. Standard<\/th>\n<\/tr>\n<\/thead>\n \n\n1xxx<\/td>\n < 0.05<\/td>\n Standard cover flux<\/td>\n 8 – 12<\/td>\n Baseline<\/td>\n<\/tr>\n \n2xxx<\/td>\n < 0.05<\/td>\n Standard cover flux<\/td>\n 8 – 12<\/td>\n +10% for higher temp<\/td>\n<\/tr>\n \n3xxx<\/td>\n < 0.05<\/td>\n Standard cover flux<\/td>\n 8 – 12<\/td>\n Baseline<\/td>\n<\/tr>\n \n4xxx casting<\/td>\n < 0.10<\/td>\n Standard or low-temp flux<\/td>\n 8 – 15<\/td>\n Baseline to +10%<\/td>\n<\/tr>\n \n5xxx (2-4% Mg)<\/td>\n 2.0 – 4.0<\/td>\n High-Mg cover flux<\/td>\n 15 – 20<\/td>\n +30 – 50%<\/td>\n<\/tr>\n \n5xxx (4-6% Mg)<\/td>\n 4.0 – 6.0<\/td>\n Premium high-Mg flux<\/td>\n 20 – 28<\/td>\n +50 – 75%<\/td>\n<\/tr>\n \n6xxx<\/td>\n 0.2 – 1.2<\/td>\n Standard or mid-fluoride<\/td>\n 10 – 16<\/td>\n +10 – 20%<\/td>\n<\/tr>\n \n7xxx<\/td>\n 1.0 – 3.0<\/td>\n High-Mg \/ high-fluoride<\/td>\n 16 – 24<\/td>\n +30 – 50%<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\nHow Cover Flux Affects Dross Formation and Metal Recovery<\/h2>\nThe Direct Relationship Between Cover Flux Quality and Metal Yield<\/h3>\n Dross is the most visible consequence of poor cover flux performance. Every kilogram of dross generated represents both direct metal loss (dross typically contains 40-80% entrapped aluminium metal, depending on how it is managed) and indirect costs \u2014 labour for skimming, dross processing or disposal, and downstream quality problems from dross particles contaminating the melt.<\/p>\n
The financial impact of dross generation is substantial. In a foundry melting 10 tonnes of aluminium per day with a dross rate of 3% (300 kg dross per day) and a metal recovery from dross of 60%, the gross daily metal loss from dross is 120 kg of aluminium. At current aluminium prices, this represents a significant daily cost that accumulates quickly over a month or year of operation.<\/p>\n
Cover flux impact on dross generation:<\/strong><\/p>\nThe primary mechanism by which cover flux reduces dross is continuous suppression of the oxide formation rate at the melt surface. Less oxide formation means less material to entrap metal droplets, less dross volume generated, and higher metal recovery from the dross that does form.<\/p>\n
Studies conducted across multiple foundry operations consistently show:<\/p>\n
\nOperations without cover flux: dross rate 3-6% of melt weight.<\/li>\n Operations with standard cover flux at correct dosage: dross rate 1.5-3% of melt weight.<\/li>\n Operations with optimal cover flux formulation and dosage: dross rate 0.8-1.8% of melt weight.<\/li>\n<\/ul>\nAdditionally, dross formed under a protective flux layer has higher metal content and is easier to recover than dross formed on an unprotected melt surface. Under-flux dross tends to be a dry, crumbly mixture with 40-55% metal content. Well-formed dross from a properly fluxed operation is a wetter, more fluid material with 60-80% metal content that can be more efficiently processed in a dross press or rotary salt furnace.<\/p>\n
Dross generation comparison by cover flux practice:<\/strong><\/p>\n\n
\n\n\nCover Flux Practice<\/th>\n Dross Rate (% of melt wt.)<\/th>\n Metal in Dross (%)<\/th>\n Net Metal Loss (%)<\/th>\n Cost Impact vs. No Flux<\/th>\n<\/tr>\n<\/thead>\n \n\nNo cover flux<\/td>\n 4.5 – 6.0<\/td>\n 40 – 55<\/td>\n 2.2 – 3.3<\/td>\n Baseline (highest cost)<\/td>\n<\/tr>\n \nIncorrect flux type<\/td>\n 3.5 – 5.0<\/td>\n 45 – 60<\/td>\n 1.8 – 2.8<\/td>\n -15 to -20%<\/td>\n<\/tr>\n \nUnderdosed standard flux<\/td>\n 2.5 – 4.0<\/td>\n 50 – 65<\/td>\n 1.2 – 2.0<\/td>\n -30 to -40%<\/td>\n<\/tr>\n \nOptimal standard flux<\/td>\n 1.5 – 2.5<\/td>\n 60 – 75<\/td>\n 0.6 – 1.0<\/td>\n -55 to -70%<\/td>\n<\/tr>\n \nOptimal high-Mg flux (5xxx)<\/td>\n 1.8 – 3.0<\/td>\n 62 – 78<\/td>\n 0.7 – 1.2<\/td>\n -50 to -65%<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\nEnvironmental and Safety Considerations: Fluoride Content and Workplace Exposure<\/h2>\nManaging Fluoride Emissions and Worker Safety in Flux Operations<\/h3>\n Fluoride-containing cover fluxes generate gaseous fluoride compounds during operation \u2014 primarily hydrogen fluoride (HF) and silicon tetrafluoride (SiF\u2084) from reactions between fluoride salts and silica-containing materials. These emissions require careful management to protect worker health and meet environmental regulations.<\/p>\n
Hydrogen fluoride (HF) exposure limits:<\/strong><\/p>\n\n
\n\n\nRegulatory Body<\/th>\n HF Exposure Limit<\/th>\n Time Basis<\/th>\n<\/tr>\n<\/thead>\n \n\nOSHA (USA)<\/td>\n 3 ppm<\/td>\n 8-hour TWA<\/td>\n<\/tr>\n \nACGIH (USA)<\/td>\n 0.5 ppm<\/td>\n Ceiling (instantaneous)<\/td>\n<\/tr>\n \nEU (EH40)<\/td>\n 1 ppm<\/td>\n 8-hour TWA<\/td>\n<\/tr>\n \nUK HSE (WEL)<\/td>\n 1 ppm<\/td>\n 8-hour TWA<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\nAt typical aluminium foundry flux application rates, HF concentrations at the furnace operator position can reach 1-5 ppm without ventilation controls \u2014 potentially exceeding regulatory limits depending on jurisdiction.<\/p>\n
Engineering controls for fluoride emission management:<\/strong><\/p>\nLocal exhaust ventilation (LEV) installed directly above or alongside the furnace opening is the primary control measure. The LEV system captures fluoride-containing gases at the generation point before they disperse into the working environment. Requirements include:<\/p>\n
\nCapture velocity at the furnace opening: minimum 0.5-1.0 m\/s.<\/li>\n Exhaust volume: calculated based on furnace opening area and operating temperature.<\/li>\n Treatment of exhaust gases: wet scrubbing (sodium hydroxide solution) or dry lime injection before atmospheric discharge.<\/li>\n Regular monitoring of airborne HF concentrations at operator positions.<\/li>\n<\/ul>\nPersonal protective equipment (PPE) for flux handling:<\/strong><\/p>\n\n
\n\n\nTask<\/th>\n Required PPE<\/th>\n<\/tr>\n<\/thead>\n \n\nFlux storage and handling<\/td>\n Nitrile gloves, dust mask (P2\/FFP2), safety glasses<\/td>\n<\/tr>\n \nFlux application to melt<\/td>\n Heat-resistant gloves, face shield, dust mask, protective clothing<\/td>\n<\/tr>\n \nSkimming fluxed dross<\/td>\n Face shield, heat-resistant gloves and sleeves, respiratory protection<\/td>\n<\/tr>\n \nWorking near furnace during flux operation<\/td>\n Supplied air respirator recommended in high-fluoride environments<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\nLow-fluoride and fluoride-free flux alternatives:<\/strong><\/p>\nGrowing regulatory pressure on fluoride emissions has driven development of reduced-fluoride and fluoride-free cover flux formulations. These products substitute borate compounds, phosphate additions, and specialised organic carriers for some or all of the fluoride content. The tradeoff is typically reduced oxide dissolution performance \u2014 physical barrier protection is maintained, but chemical dissolution of forming oxide is less effective. For low-to-moderate risk operations (pure aluminium, low-Mg alloys, clean melts), low-fluoride fluxes can provide adequate protection with substantially reduced HF emissions.<\/p>\n
Quality Indicators: How to Evaluate Cover Flux Before and During Use<\/h2>\nWhat to Check When Qualifying a Cover Flux Supplier<\/h3>\n Cover flux quality varies considerably between suppliers, and purchasing based on price alone without specification verification frequently leads to operational problems that cost far more than the price difference saved. We have audited several foundry operations where substandard flux purchased at a 15-20% discount resulted in dross rates double those achievable with a quality product \u2014 the financial loss from excess dross far exceeded the flux cost savings.<\/p>\n
Key quality parameters to specify and verify:<\/strong><\/p>\n\n
\n\n\nParameter<\/th>\n Why It Matters<\/th>\n Test Method<\/th>\n Typical Specification<\/th>\n<\/tr>\n<\/thead>\n \n\nChemical composition<\/td>\n Incorrect NaCl\/KCl\/fluoride ratio affects melting point and performance<\/td>\n XRF or wet chemical analysis<\/td>\n Per formulation specification<\/td>\n<\/tr>\n \nMelting point \/ liquidus<\/td>\n Flux must melt below aluminium processing temperature<\/td>\n DSC (Differential Scanning Calorimetry)<\/td>\n 550 – 650\u00b0C<\/td>\n<\/tr>\n \nMoisture content<\/td>\n Moisture releases steam on contact with melt, causing spattering and hydrogen pickup<\/td>\n Karl Fischer titration<\/td>\n < 0.5% by weight<\/td>\n<\/tr>\n \nParticle size distribution<\/td>\n Affects melting speed and dust generation<\/td>\n Sieve analysis<\/td>\n Per agreed specification<\/td>\n<\/tr>\n \nBulk density<\/td>\n Affects dosage by volume vs. weight<\/td>\n Tap density measurement<\/td>\n Per agreed specification<\/td>\n<\/tr>\n \nFluoride content (total)<\/td>\n Determines oxide dissolution capability and emission potential<\/td>\n Ion selective electrode<\/td>\n Per formulation specification<\/td>\n<\/tr>\n \nHeavy metal impurities<\/td>\n Lead, cadmium, mercury must be absent in food-contact or sensitive applications<\/td>\n ICP-OES analysis<\/td>\n Below regulatory limits<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\nIn-use quality assessment:<\/strong><\/p>\nThe most practical quality check during production is observation of the flux behaviour on the melt surface:<\/p>\n
\nGood quality flux:<\/strong> melts rapidly and smoothly, spreads uniformly across the melt surface, forms a continuous molten layer with a slightly oily or glassy appearance, remains fluid at operating temperature without excessive thickening.<\/li>\nPoor quality flux:<\/strong> melts unevenly, leaves dry patches, forms a thick, pasty layer that does not spread, produces excessive fumes on contact with melt, or causes spattering (indicating moisture contamination).<\/li>\n<\/ul>\nMoisture contamination<\/strong>\u00a0is the most common quality problem with chloride-based fluxes. Even flux that left the factory with acceptable moisture content can absorb significant atmospheric moisture during shipping and storage. Flux stored in damaged or partially opened bags in a humid warehouse for several weeks can reach moisture contents above 2-3%, which causes violent steam release and spattering when applied to a melt at 720-750\u00b0C \u2014 a significant safety hazard. Always store flux in sealed, undamaged bags in a dry area, and consider purchasing in smaller bag sizes if usage rate is low.<\/p>\nCover Flux for High-Magnesium Alloys: Special Formulation Requirements<\/h2>\nWhy Standard Cover Flux Fails on 5xxx and 7xxx Series Aluminium<\/h3>\n High-magnesium aluminium alloys present the most challenging cover flux application in the foundry industry. The failure mode is specific and consistent: an operator who has successfully used a standard NaCl-KCl flux on 1xxx or 4xxx alloys switches to 5xxx alloy production without changing the flux formulation, and observes dramatically increased dross formation, frequent surface fires (burning of the magnesium-rich dross in air), and deteriorating melt quality.<\/p>\n
The root cause is that standard cover flux has inadequate fluoride content to dissolve and incorporate MgO and MgAl\u2082O\u2084 spinel as these form at the melt surface. Without effective oxide dissolution, the oxide layer thickens, entraps metal, and eventually burns in the furnace atmosphere \u2014 generating additional oxide and heat in a self-sustaining reaction.<\/p>\n
Requirements for a cover flux suitable for high-magnesium alloys:<\/strong><\/p>\nHigher total fluoride content (18-28%):<\/strong>\u00a0Sufficient fluoride activity to continuously dissolve MgO and spinel as they form, preventing accumulation of a reactive oxide layer.<\/p>\nModified base salt system:<\/strong>\u00a0Some high-Mg flux formulations incorporate BaCl\u2082 (barium chloride) or CaCl\u2082 (calcium chloride) at 5-15% to improve wetting characteristics on the magnesium-rich surface and to increase the density of the molten flux layer (better coverage under turbulent conditions).<\/p>\nControlled viscosity:<\/strong>\u00a0The molten flux must remain fluid enough to flow into surface disruptions caused by convection currents but viscous enough not to slide off the surface during charging operations. High-Mg flux formulations balance these requirements through careful CaF\u2082 content adjustment.<\/p>\nHigher application rate:<\/strong>\u00a0Due to the faster oxidation rate of Mg-containing alloys, dosage rates for high-Mg cover flux are typically 30-75% higher than for equivalent standard cover flux applications.<\/p>\nSuppression of burning reactions:<\/strong>\u00a0Some specialised formulations include small additions of inhibiting compounds (borates or specialised proprietary additives) that elevate the ignition temperature of the dross surface, preventing the surface burning events that cause rapid metal loss in high-Mg alloy melts.<\/p>\nCost-Benefit Analysis: Calculating the Return from Cover Flux Use<\/h2>\nQuantifying the Financial Case for Cover Flux Investment<\/h3>\n The economic justification for cover flux use is straightforward to calculate once you know your current dross generation rate and aluminium price. Here is a worked example based on a medium-sized aluminium foundry:<\/p>\n
Baseline operation (no cover flux):<\/strong><\/p>\n\nDaily melt throughput: 8 tonnes aluminium<\/li>\n Dross generation rate: 4.5% (360 kg dross per day)<\/li>\n Metal content in dross: 50% (180 kg recoverable metal per day, 180 kg lost)<\/li>\n Current aluminium price: $2,400 per tonne<\/li>\n Daily metal loss value: 180 kg \u00d7 $2.40 = $432 per day<\/li>\n Annual metal loss value: $432 \u00d7 300 working days = $129,600<\/li>\n<\/ul>\nWith optimised cover flux application:<\/strong><\/p>\n\nCover flux dosage: 2.5 kg per tonne = 20 kg per day<\/li>\n Cover flux cost: $2.50 per kg = $50 per day<\/li>\n New dross generation rate: 1.8% (144 kg dross per day)<\/li>\n Metal content in dross: 68% (97.9 kg recoverable, 46 kg lost)<\/li>\n Daily metal loss value: 46 kg \u00d7 $2.40 = $110 per day<\/li>\n Annual metal loss value: $110 \u00d7 300 = $33,000<\/li>\n<\/ul>\nNet annual saving:<\/strong><\/p>\n\nMetal loss reduction: $129,600 – $33,000 = $96,600<\/li>\n Annual flux cost: $50 \u00d7 300 = $15,000<\/li>\n Net annual saving: $96,600 – $15,000 =\u00a0$81,600<\/strong><\/li>\nReturn on flux investment:\u00a0544%<\/strong><\/li>\n<\/ul>\nThis calculation is conservative \u2014 it excludes savings from reduced skimming labour, improved casting quality (lower scrap rates), reduced furnace maintenance (less oxide buildup on furnace walls), and improved consistency of alloy composition.<\/p>\n
Sensitivity analysis \u2014 net saving at different metal prices:<\/strong><\/p>\n\n
\n\n\nAluminium Price ($\/tonne)<\/th>\n Daily Metal Loss Saving ($)<\/th>\n Annual Net Saving ($)<\/th>\n ROI on Flux Cost<\/th>\n<\/tr>\n<\/thead>\n \n\n$1,800<\/td>\n $240<\/td>\n $57,000<\/td>\n 380%<\/td>\n<\/tr>\n \n$2,200<\/td>\n $310<\/td>\n $72,000<\/td>\n 480%<\/td>\n<\/tr>\n \n$2,400<\/td>\n $322<\/td>\n $81,600<\/td>\n 544%<\/td>\n<\/tr>\n \n$2,800<\/td>\n $385<\/td>\n $100,500<\/td>\n 670%<\/td>\n<\/tr>\n \n$3,200<\/td>\n $450<\/td>\n $120,000<\/td>\n 800%<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\nAcross any realistic aluminium price range, the return on cover flux investment is highly positive. The economic case is strongest at higher metal prices, but even at historically low aluminium prices, cover flux use returns multiple times its cost in metal yield improvement alone.<\/p>\n
FAQs<\/h2>\n Q1: What is cover flux for aluminium and what does it do?<\/strong><\/p>\nCover flux is a mixture of inorganic salts \u2014 primarily sodium chloride, potassium chloride, and fluoride compounds \u2014 applied to the surface of liquid aluminium in a furnace or ladle. It creates a molten salt barrier that physically separates the aluminium melt from the furnace atmosphere, preventing oxidation by atmospheric oxygen and moisture. The fluoride components in the flux also chemically dissolve aluminium oxide as it forms at the melt surface, suppressing dross generation. The result is lower metal loss, cleaner melt, and reduced downstream casting defects.<\/p>\n
Q2: How do you apply cover flux to liquid aluminium?<\/strong><\/p>\nCover flux is applied by distributing the material evenly across the entire melt surface \u2014 including corners and edges \u2014 using a sieve, perforated scoop, or automated dispensing system. An initial charge of 2-4 kg per tonne of aluminium establishes the protective layer. Subsequent maintenance additions of 0.5-1.5 kg per tonne per hour are made at regular intervals (every 30-90 minutes depending on furnace type) to compensate for flux consumed or skimmed with dross. The flux must cover the complete melt surface continuously \u2014 bare areas are not protected.<\/p>\n
Q3: What is the difference between cover flux and drossing flux?<\/strong><\/p>\nCover flux is applied continuously at low dosage rates to protect the melt surface from oxidation throughout the melting and holding period. Drossing flux (cleaning flux) is applied periodically at higher dosage rates and stirred into the melt or dross to incorporate oxide inclusions into the flux phase for removal. Cover flux prevents dross from forming; drossing flux helps remove dross that has already formed. The two products have different chemical compositions \u2014 drossing fluxes are typically higher in fluoride content and more chemically aggressive.<\/p>\n
Q4: How much cover flux should I use per tonne of aluminium?<\/strong><\/p>\nThe recommended initial dosage is 2-4 kg of cover flux per tonne of aluminium, with maintenance additions of 0.5-1.5 kg per tonne per hour. Exact dosage depends on furnace type, alloy composition, melt temperature, and environmental humidity. High-magnesium alloys (5xxx, 7xxx series) require 30-75% higher dosage rates than standard alloys due to their higher oxidation rate. Electric furnaces require lower dosage than gas-fired furnaces because there is no combustion atmosphere above the melt.<\/p>\n
Q5: Can I use cover flux on all aluminium alloys?<\/strong><\/p>\nStandard cover flux formulations (NaCl-KCl with 8-15% fluoride) are suitable for most aluminium alloys with low magnesium content \u2014 1xxx, 2xxx, 3xxx, 4xxx casting alloys, and lower-Mg 6xxx alloys. High-magnesium alloys (5xxx series above 2% Mg, 7xxx series, and high-Mg 6xxx alloys) require specially formulated high-magnesium cover flux with higher fluoride content (15-28%) to effectively dissolve MgO and spinel inclusions. Using a standard flux on high-Mg alloys results in inadequate protection, excessive dross, and potentially dangerous surface burning reactions.<\/p>\n
Q6: Is cover flux hazardous to use? What safety precautions are needed?<\/strong><\/p>\nCover flux contains chloride and fluoride salts that generate hydrogen fluoride (HF) gas when heated in contact with moisture or when in contact with liquid aluminium. HF is a toxic gas with a regulatory exposure limit of 0.5-3 ppm depending on jurisdiction. Foundry operators applying or working near cover flux should wear appropriate PPE including heat-resistant gloves, face shields, and respiratory protection. Local exhaust ventilation should be installed above furnace openings to capture emissions. Flux should be stored in sealed bags in a dry location to prevent moisture absorption that worsens HF generation.<\/p>\n
Q7: Why is my aluminium melt producing excessive dross even with cover flux?<\/strong><\/p>\nExcessive dross despite cover flux use typically indicates one or more of the following problems: incorrect flux formulation for the alloy being processed (particularly if processing high-Mg alloys with standard flux); insufficient dosage or application frequency leaving areas of melt surface unprotected; moisture-contaminated flux that is partially decomposing before providing protection; melt temperature too high for the operating conditions; mechanical disruption of the flux layer from scrap charging or excessive stirring without subsequent flux replenishment; or burner flames impinging directly on the melt surface and burning through the flux layer.<\/p>\n
Q8: How should cover flux be stored to maintain its quality?<\/strong><\/p>\nStore cover flux in its original, sealed packaging in a clean, dry indoor location away from moisture sources. Chloride-fluoride salt mixtures are hygroscopic \u2014 they absorb moisture from the air, which degrades their performance and creates a safety hazard (moisture in flux causes spattering and HF generation when the flux contacts liquid aluminium). Bags that have been opened and only partially used should be resealed immediately with tape or clips. Avoid storing flux near water pipes, outdoor areas, or humid environments. First-in, first-out stock rotation ensures older material is used before moisture absorption becomes significant.<\/p>\n
Q9: Does cover flux affect the chemical composition of the aluminium melt?<\/strong><\/p>\nCorrectly applied cover flux at recommended dosage rates has minimal effect on aluminium melt composition. Small amounts of sodium from NaCl\/NaF can dissolve into the melt \u2014 sodium embrittlement is a concern in some 6xxx and 7xxx alloys. This is managed by using potassium-based flux formulations where sodium pickup is critical, or by limiting contact time between the flux and the melt at operating temperature. Fluoride contamination of the melt is negligible at correct dosage rates. Flux that is stirred into the melt (rather than resting on the surface) significantly increases the risk of compositional contamination and should be avoided except for deliberate cleaning flux treatments.<\/p>\n
Q10: What is the environmental impact of aluminium cover flux disposal?<\/strong><\/p>\nUsed cover flux mixed with dross contains chloride and fluoride salts that are classified as hazardous waste in many jurisdictions due to leaching potential. The salt-rich dross fraction generated from fluxed operations should be processed through a dross press to recover trapped metal and then the salt cake should be sent to a licensed processing facility. Modern secondary aluminium facilities use closed-loop salt recovery systems where the salt cake is reprocessed in rotary salt furnaces, recovering additional metal and regenerating the salt for reuse. Direct landfill disposal of flux-containing salt cake is prohibited or heavily regulated in the EU, North America, and many other regions.<\/p>\n
Conclusion: Choosing the Right Cover Flux for Your Aluminium Foundry<\/h2>\n Cover flux for aluminium is a small-cost, high-impact consumable that sits at the intersection of metal yield, melt quality, and operational safety. The correct selection and application of cover flux consistently delivers a return of 400-800% on consumable cost through reduced metal loss alone, before accounting for downstream quality improvements.<\/p>\n
The key decisions in cover flux selection are:<\/p>\n
Alloy compatibility:<\/strong>\u00a0Match the fluoride content and base salt system to your alloy’s magnesium level. Standard flux for low-Mg alloys; dedicated high-Mg formulation for 5xxx, 7xxx, and high-Mg 6xxx alloys.<\/p>\nPhysical form:<\/strong>\u00a0Granule for most manual foundry operations; tablet for automated addition and holding furnaces; powder only where automated dispensing is available and dust exposure is controlled.<\/p>\nDosage discipline:<\/strong>\u00a0Apply at the recommended rate consistently \u2014 underdosing is a false economy that costs more in metal loss than the flux savings are worth.<\/p>\nStorage and handling:<\/strong>\u00a0Keep flux dry, sealed, and protected from moisture from delivery to point of use. Moisture-contaminated flux creates both safety hazards and performance problems.<\/p>\nQuick reference: Cover flux selection summary:<\/strong><\/p>\n\n
\n\n\nAlloy Type<\/th>\n Mg Content<\/th>\n Flux Type<\/th>\n Starting Dosage (kg\/tonne)<\/th>\n Special Considerations<\/th>\n<\/tr>\n<\/thead>\n \n\n1xxx, 2xxx, 3xxx<\/td>\n < 0.1%<\/td>\n Standard cover flux<\/td>\n 2.0 – 3.0<\/td>\n Standard application<\/td>\n<\/tr>\n \n4xxx casting alloys<\/td>\n < 0.1%<\/td>\n Standard or low-temp flux<\/td>\n 2.0 – 3.5<\/td>\n Check melting point matches operating temp<\/td>\n<\/tr>\n \n6xxx (low Mg)<\/td>\n 0.2 – 0.6%<\/td>\n Standard to mid-fluoride<\/td>\n 2.5 – 3.5<\/td>\n Monitor sodium pickup<\/td>\n<\/tr>\n \n6xxx (high Mg)<\/td>\n 0.6 – 1.2%<\/td>\n Mid-fluoride flux<\/td>\n 3.0 – 4.0<\/td>\n Increase dosage in humid conditions<\/td>\n<\/tr>\n \n5xxx (2-4% Mg)<\/td>\n 2.0 – 4.0%<\/td>\n High-Mg cover flux<\/td>\n 3.5 – 5.0<\/td>\n Dedicated high-fluoride formulation required<\/td>\n<\/tr>\n \n5xxx (4-6% Mg)<\/td>\n 4.0 – 6.0%<\/td>\n Premium high-Mg flux<\/td>\n 4.5 – 6.5<\/td>\n Monitor for surface burning, increase frequency<\/td>\n<\/tr>\n \n7xxx<\/td>\n 1.0 – 3.0%<\/td>\n High-Mg \/ high-fluoride<\/td>\n 3.5 – 5.5<\/td>\n Manage fluoride emissions<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\nAdTech supplies cover flux, cleaning flux, grain refining flux, and complete melt treatment solutions to aluminium foundries and casting operations globally. Our technical team provides flux selection support, application protocol development, and dosage optimisation services based on your specific alloy range, furnace configuration, and quality requirements.<\/p>\n","protected":false},"excerpt":{"rendered":"
Cover flux for aluminium is a specially formulated mixture of inorganic salts applied directly to the surface of liquid aluminium in melting furnaces, holding furnaces, and ladles to create a physical and chemical barrier between the melt and the furnace atmosphere \u2014 and when correctly selected and applied, it measurably reduces metal oxidation losses by […]<\/p>\n","protected":false},"author":1,"featured_media":3450,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"default","adv-header-id-meta":"","stick-header-meta":"default","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[1],"tags":[],"class_list":["post-3449","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news"],"acf":[],"yoast_head":"\n
Cover Flux for Aluminium | Reduce Oxidation Foundry Supply - AdTech<\/title>\n<meta name=\"description\" content=\"Source premium cover flux for aluminium melting. High-efficiency granular & powder fluxes to reduce oxidation loss, improve dross separation & purify molten metal.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.c-adtech.com\/de\/cover-flux-for-aluminium-reduce-oxidation-foundry-supply\/\" \/>\n<meta property=\"og:locale\" content=\"de_DE\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Cover Flux for Aluminium | Reduce Oxidation Foundry Supply - AdTech\" \/>\n<meta property=\"og:description\" content=\"Source premium cover flux for aluminium melting. High-efficiency granular & powder fluxes to reduce oxidation loss, improve dross separation & purify molten metal.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.c-adtech.com\/de\/cover-flux-for-aluminium-reduce-oxidation-foundry-supply\/\" \/>\n<meta property=\"og:site_name\" content=\"AdTech\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/people\/AdTech-Metallurgical-Materials-Co-Ltd\/100064039905332\/\" \/>\n<meta property=\"article:published_time\" content=\"2026-07-09T08:56:20+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/www.c-adtech.com\/wp-content\/uploads\/2026\/07\/9178_Dby3RSgp.webp\" \/>\n\t<meta property=\"og:image:width\" content=\"538\" \/>\n\t<meta property=\"og:image:height\" content=\"538\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/webp\" \/>\n<meta name=\"author\" content=\"AdTech\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Verfasst von\" \/>\n\t<meta name=\"twitter:data1\" content=\"AdTech\" \/>\n\t<meta name=\"twitter:label2\" content=\"Gesch\u00e4tzte Lesezeit\" \/>\n\t<meta name=\"twitter:data2\" content=\"31\u00a0Minuten\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\/\/www.c-adtech.com\/cover-flux-for-aluminium-reduce-oxidation-foundry-supply\/#article\",\"isPartOf\":{\"@id\":\"https:\/\/www.c-adtech.com\/cover-flux-for-aluminium-reduce-oxidation-foundry-supply\/\"},\"author\":{\"name\":\"AdTech\",\"@id\":\"https:\/\/www.c-adtech.com\/es\/#\/schema\/person\/281af53461a6a2f505ceba0c8e66479f\"},\"headline\":\"Cover Flux for Aluminium | Reduce Oxidation Foundry Supply\",\"datePublished\":\"2026-07-09T08:56:20+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/www.c-adtech.com\/cover-flux-for-aluminium-reduce-oxidation-foundry-supply\/\"},\"wordCount\":6549,\"commentCount\":0,\"publisher\":{\"@id\":\"https:\/\/www.c-adtech.com\/es\/#organization\"},\"image\":{\"@id\":\"https:\/\/www.c-adtech.com\/cover-flux-for-aluminium-reduce-oxidation-foundry-supply\/#primaryimage\"},\"thumbnailUrl\":\"https:\/\/www.c-adtech.com\/wp-content\/uploads\/2026\/07\/9178_Dby3RSgp.webp\",\"articleSection\":[\"News\"],\"inLanguage\":\"de\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\/\/www.c-adtech.com\/cover-flux-for-aluminium-reduce-oxidation-foundry-supply\/#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.c-adtech.com\/cover-flux-for-aluminium-reduce-oxidation-foundry-supply\/\",\"url\":\"https:\/\/www.c-adtech.com\/cover-flux-for-aluminium-reduce-oxidation-foundry-supply\/\",\"name\":\"Cover Flux for Aluminium | Reduce Oxidation Foundry Supply - AdTech\",\"isPartOf\":{\"@id\":\"https:\/\/www.c-adtech.com\/es\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/www.c-adtech.com\/cover-flux-for-aluminium-reduce-oxidation-foundry-supply\/#primaryimage\"},\"image\":{\"@id\":\"https:\/\/www.c-adtech.com\/cover-flux-for-aluminium-reduce-oxidation-foundry-supply\/#primaryimage\"},\"thumbnailUrl\":\"https:\/\/www.c-adtech.com\/wp-content\/uploads\/2026\/07\/9178_Dby3RSgp.webp\",\"datePublished\":\"2026-07-09T08:56:20+00:00\",\"description\":\"Source premium cover flux for aluminium melting. High-efficiency granular & powder fluxes to reduce oxidation loss, improve dross separation & purify molten metal.\",\"breadcrumb\":{\"@id\":\"https:\/\/www.c-adtech.com\/cover-flux-for-aluminium-reduce-oxidation-foundry-supply\/#breadcrumb\"},\"inLanguage\":\"de\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/www.c-adtech.com\/cover-flux-for-aluminium-reduce-oxidation-foundry-supply\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"de\",\"@id\":\"https:\/\/www.c-adtech.com\/cover-flux-for-aluminium-reduce-oxidation-foundry-supply\/#primaryimage\",\"url\":\"https:\/\/www.c-adtech.com\/wp-content\/uploads\/2026\/07\/9178_Dby3RSgp.webp\",\"contentUrl\":\"https:\/\/www.c-adtech.com\/wp-content\/uploads\/2026\/07\/9178_Dby3RSgp.webp\",\"width\":538,\"height\":538,\"caption\":\"Cover Flux for Aluminium\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/www.c-adtech.com\/cover-flux-for-aluminium-reduce-oxidation-foundry-supply\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/www.c-adtech.com\/es\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Cover Flux for Aluminium | Reduce Oxidation Foundry Supply\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.c-adtech.com\/es\/#website\",\"url\":\"https:\/\/www.c-adtech.com\/es\/\",\"name\":\"AdTech\",\"description\":\"Aluminum Degassing, Filtration Equipment\",\"publisher\":{\"@id\":\"https:\/\/www.c-adtech.com\/es\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/www.c-adtech.com\/es\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"de\"},{\"@type\":\"Organization\",\"@id\":\"https:\/\/www.c-adtech.com\/es\/#organization\",\"name\":\"AdTech\",\"url\":\"https:\/\/www.c-adtech.com\/es\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"de\",\"@id\":\"https:\/\/www.c-adtech.com\/es\/#\/schema\/logo\/image\/\",\"url\":\"https:\/\/www.c-adtech.com\/wp-content\/uploads\/2025\/11\/logo.webp\",\"contentUrl\":\"https:\/\/www.c-adtech.com\/wp-content\/uploads\/2025\/11\/logo.webp\",\"width\":230,\"height\":70,\"caption\":\"AdTech\"},\"image\":{\"@id\":\"https:\/\/www.c-adtech.com\/es\/#\/schema\/logo\/image\/\"},\"sameAs\":[\"https:\/\/www.facebook.com\/people\/AdTech-Metallurgical-Materials-Co-Ltd\/100064039905332\/\"]},{\"@type\":\"Person\",\"@id\":\"https:\/\/www.c-adtech.com\/es\/#\/schema\/person\/281af53461a6a2f505ceba0c8e66479f\",\"name\":\"AdTech\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"de\",\"@id\":\"https:\/\/www.c-adtech.com\/es\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/secure.gravatar.com\/avatar\/13cb064168280db4825e8f0703d11161?s=96&d=mm&r=g\",\"contentUrl\":\"https:\/\/secure.gravatar.com\/avatar\/13cb064168280db4825e8f0703d11161?s=96&d=mm&r=g\",\"caption\":\"AdTech\"},\"sameAs\":[\"http:\/\/www.c-adtech.com\"],\"url\":\"https:\/\/www.c-adtech.com\/de\/author\/admin\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Cover Flux for Aluminium | Reduce Oxidation Foundry Supply - AdTech","description":"Source premium cover flux for aluminium melting. High-efficiency granular & powder fluxes to reduce oxidation loss, improve dross separation & purify molten metal.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.c-adtech.com\/de\/cover-flux-for-aluminium-reduce-oxidation-foundry-supply\/","og_locale":"de_DE","og_type":"article","og_title":"Cover Flux for Aluminium | Reduce Oxidation Foundry Supply - AdTech","og_description":"Source premium cover flux for aluminium melting. High-efficiency granular & powder fluxes to reduce oxidation loss, improve dross separation & purify molten metal.","og_url":"https:\/\/www.c-adtech.com\/de\/cover-flux-for-aluminium-reduce-oxidation-foundry-supply\/","og_site_name":"AdTech","article_publisher":"https:\/\/www.facebook.com\/people\/AdTech-Metallurgical-Materials-Co-Ltd\/100064039905332\/","article_published_time":"2026-07-09T08:56:20+00:00","og_image":[{"width":538,"height":538,"url":"https:\/\/www.c-adtech.com\/wp-content\/uploads\/2026\/07\/9178_Dby3RSgp.webp","type":"image\/webp"}],"author":"AdTech","twitter_card":"summary_large_image","twitter_misc":{"Verfasst von":"AdTech","Gesch\u00e4tzte Lesezeit":"31\u00a0Minuten"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/www.c-adtech.com\/cover-flux-for-aluminium-reduce-oxidation-foundry-supply\/#article","isPartOf":{"@id":"https:\/\/www.c-adtech.com\/cover-flux-for-aluminium-reduce-oxidation-foundry-supply\/"},"author":{"name":"AdTech","@id":"https:\/\/www.c-adtech.com\/es\/#\/schema\/person\/281af53461a6a2f505ceba0c8e66479f"},"headline":"Cover Flux for Aluminium | Reduce Oxidation Foundry Supply","datePublished":"2026-07-09T08:56:20+00:00","mainEntityOfPage":{"@id":"https:\/\/www.c-adtech.com\/cover-flux-for-aluminium-reduce-oxidation-foundry-supply\/"},"wordCount":6549,"commentCount":0,"publisher":{"@id":"https:\/\/www.c-adtech.com\/es\/#organization"},"image":{"@id":"https:\/\/www.c-adtech.com\/cover-flux-for-aluminium-reduce-oxidation-foundry-supply\/#primaryimage"},"thumbnailUrl":"https:\/\/www.c-adtech.com\/wp-content\/uploads\/2026\/07\/9178_Dby3RSgp.webp","articleSection":["News"],"inLanguage":"de","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/www.c-adtech.com\/cover-flux-for-aluminium-reduce-oxidation-foundry-supply\/#respond"]}]},{"@type":"WebPage","@id":"https:\/\/www.c-adtech.com\/cover-flux-for-aluminium-reduce-oxidation-foundry-supply\/","url":"https:\/\/www.c-adtech.com\/cover-flux-for-aluminium-reduce-oxidation-foundry-supply\/","name":"Cover Flux for Aluminium | Reduce Oxidation Foundry Supply - AdTech","isPartOf":{"@id":"https:\/\/www.c-adtech.com\/es\/#website"},"primaryImageOfPage":{"@id":"https:\/\/www.c-adtech.com\/cover-flux-for-aluminium-reduce-oxidation-foundry-supply\/#primaryimage"},"image":{"@id":"https:\/\/www.c-adtech.com\/cover-flux-for-aluminium-reduce-oxidation-foundry-supply\/#primaryimage"},"thumbnailUrl":"https:\/\/www.c-adtech.com\/wp-content\/uploads\/2026\/07\/9178_Dby3RSgp.webp","datePublished":"2026-07-09T08:56:20+00:00","description":"Source premium cover flux for aluminium melting. High-efficiency granular & powder fluxes to reduce oxidation loss, improve dross separation & purify molten metal.","breadcrumb":{"@id":"https:\/\/www.c-adtech.com\/cover-flux-for-aluminium-reduce-oxidation-foundry-supply\/#breadcrumb"},"inLanguage":"de","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.c-adtech.com\/cover-flux-for-aluminium-reduce-oxidation-foundry-supply\/"]}]},{"@type":"ImageObject","inLanguage":"de","@id":"https:\/\/www.c-adtech.com\/cover-flux-for-aluminium-reduce-oxidation-foundry-supply\/#primaryimage","url":"https:\/\/www.c-adtech.com\/wp-content\/uploads\/2026\/07\/9178_Dby3RSgp.webp","contentUrl":"https:\/\/www.c-adtech.com\/wp-content\/uploads\/2026\/07\/9178_Dby3RSgp.webp","width":538,"height":538,"caption":"Cover Flux for Aluminium"},{"@type":"BreadcrumbList","@id":"https:\/\/www.c-adtech.com\/cover-flux-for-aluminium-reduce-oxidation-foundry-supply\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.c-adtech.com\/es\/"},{"@type":"ListItem","position":2,"name":"Cover Flux for Aluminium | Reduce Oxidation Foundry Supply"}]},{"@type":"WebSite","@id":"https:\/\/www.c-adtech.com\/es\/#website","url":"https:\/\/www.c-adtech.com\/es\/","name":"AdTech","description":"Aluminium-Entgasung, Filtrationsanlagen","publisher":{"@id":"https:\/\/www.c-adtech.com\/es\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.c-adtech.com\/es\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"de"},{"@type":"Organization","@id":"https:\/\/www.c-adtech.com\/es\/#organization","name":"AdTech","url":"https:\/\/www.c-adtech.com\/es\/","logo":{"@type":"ImageObject","inLanguage":"de","@id":"https:\/\/www.c-adtech.com\/es\/#\/schema\/logo\/image\/","url":"https:\/\/www.c-adtech.com\/wp-content\/uploads\/2025\/11\/logo.webp","contentUrl":"https:\/\/www.c-adtech.com\/wp-content\/uploads\/2025\/11\/logo.webp","width":230,"height":70,"caption":"AdTech"},"image":{"@id":"https:\/\/www.c-adtech.com\/es\/#\/schema\/logo\/image\/"},"sameAs":["https:\/\/www.facebook.com\/people\/AdTech-Metallurgical-Materials-Co-Ltd\/100064039905332\/"]},{"@type":"Person","@id":"https:\/\/www.c-adtech.com\/es\/#\/schema\/person\/281af53461a6a2f505ceba0c8e66479f","name":"AdTech","image":{"@type":"ImageObject","inLanguage":"de","@id":"https:\/\/www.c-adtech.com\/es\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/13cb064168280db4825e8f0703d11161?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/13cb064168280db4825e8f0703d11161?s=96&d=mm&r=g","caption":"AdTech"},"sameAs":["http:\/\/www.c-adtech.com"],"url":"https:\/\/www.c-adtech.com\/de\/author\/admin\/"}]}},"_links":{"self":[{"href":"https:\/\/www.c-adtech.com\/de\/wp-json\/wp\/v2\/posts\/3449","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.c-adtech.com\/de\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.c-adtech.com\/de\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.c-adtech.com\/de\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.c-adtech.com\/de\/wp-json\/wp\/v2\/comments?post=3449"}],"version-history":[{"count":1,"href":"https:\/\/www.c-adtech.com\/de\/wp-json\/wp\/v2\/posts\/3449\/revisions"}],"predecessor-version":[{"id":3452,"href":"https:\/\/www.c-adtech.com\/de\/wp-json\/wp\/v2\/posts\/3449\/revisions\/3452"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.c-adtech.com\/de\/wp-json\/wp\/v2\/media\/3450"}],"wp:attachment":[{"href":"https:\/\/www.c-adtech.com\/de\/wp-json\/wp\/v2\/media?parent=3449"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.c-adtech.com\/de\/wp-json\/wp\/v2\/categories?post=3449"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.c-adtech.com\/de\/wp-json\/wp\/v2\/tags?post=3449"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
![\"Cover](\"https:\/\/www.c-adtech.com\/wp-content\/uploads\/2026\/07\/9178_Dby3RSgp.webp\")
![\"HOW](\"https:\/\/www.c-adtech.com\/wp-content\/uploads\/2026\/04\/2140_g4dSDbWW.webp\")
![\"Cover](\"https:\/\/www.c-adtech.com\/wp-content\/uploads\/2026\/07\/5454_YM3hb9WE.webp\")
![\"Covering](\"https:\/\/www.c-adtech.com\/wp-content\/uploads\/2026\/05\/4682_boEakYt5.webp\")
![\"Industrial](\"https:\/\/www.c-adtech.com\/wp-content\/uploads\/2026\/05\/7885_Vqb5MjBC.webp\")