Alkali Remover Sodium & Calcium Removal Flux
A few parts per million can ruin a rolling slab. Sodium at 5 to 10 ppm is enough to considerably reduce the hot rollability of aluminum-magnesium alloys, and calcium causes its own problems in aluminum-silicon. An alkali remover converts those trace metals into chlorides that leave the aluminum, and with a magnesium chloride base it does so without taking your magnesium with them.
Chelora Chemicals is an alkali remover flux supplier and sourcing partner serving casthouses, foundries and remelters across the United States. We match the grade to your alloy and your application method, with a batch COA and SDS on every consignment.
- Product type
- Alkali removal flux
- Removes
- Sodium · calcium · other alkalis
- Typical base
- MgCl₂ · KCl
- Mechanism
- Alkalis converted to chlorides
- Magnesium loss
- Avoided with MgCl₂ base
- Form
- Fused blocks, granules or powder
- Application
- Plunged, injected or rotary
- Hygroscopic
- Yes — store sealed
- Documentation
- Batch COA & SDS
Note: keep it bone dry. Magnesium chloride is strongly hygroscopic, and once hydrated it decomposes on heating to HCl and magnesium oxide, and stops working.
How an alkali remover trades metals
Magnesium chloride gives up its chlorine to sodium and calcium, and the magnesium goes into the melt.
Why it matters: chlorine and fluoride fluxing remove alkalis too, but they also take magnesium with them. A magnesium chloride base removes sodium and calcium without that loss
What an alkali remover is and does
An alkali remover is a salt flux that strips sodium, calcium and other alkali and alkaline-earth metals from molten aluminum. The common modern base is magnesium chloride with potassium chloride: the magnesium chloride reacts with sodium and calcium to form their chlorides, which separate into the salt phase, while the magnesium released goes into the metal.
Where do the alkalis come from? Primary aluminum carries traces of sodium, calcium and lithium from the electrolyte it was smelted in, and sodium-bearing fluxes and modifiers add more. In aluminum-magnesium alloys, sodium at a few parts per million causes cracking during hot rolling; in aluminum-silicon alloys, calcium above about 150 ppm is cited as harmful. Potassium chloride is added because it lowers the melting point: pure magnesium chloride melts at about 720 °C.
Alkali removal routes compared
- Chlorine gas. Effective, but means handling chlorine and loses some magnesium as MgCl₂.
- Fluoride fluxes. Effective, but also cost magnesium, as MgF₂.
- MgCl₂–KCl fluxes. Remove sodium and calcium without magnesium loss; must be kept dry.
- Rotary flux injection. Granular salt fed through a rotor, a common modern replacement for chlorine.
Handling character
Alkali remover must stay dry: hydrated magnesium chloride releases HCl on heating and is a steam hazard on molten metal. Details in the Safety section.
| Parameter | Typical value |
|---|---|
| MgCl₂ content | Per grade (patented ranges 60–80%) |
| KCl content | Balance per grade |
| Moisture | Very low — moisture-barrier pack |
| Form | Fused blocks, granules or powder |
| Granule size (injection) | Per agreed specification |
| Sodium | Low — it is what you are removing |
Important: the figures above are indicative of commercial material and are offered for planning only. The batch certificate of analysis is the governing document.
| Property | Value |
|---|---|
| Physical form | Fused blocks, granules or powder |
| Base system | MgCl₂–KCl |
| Pure MgCl₂ melting point | ≈ 720 °C |
| Mechanism | Na, Ca converted to chlorides |
| Magnesium | Retained in the melt |
| Hygroscopic | Strongly — store sealed |
| If hydrated | Decomposes to HCl and MgO on heating |
Figures for sodium and calcium effects and for MgCl₂–KCl ratios come from published patent literature on alkali removal. Exact composition, form and dose are grade-specific and stated on the producer's COA. Treat the table as orientation, not as a specification.
Where alkali removers earn their place
Rolling-alloy casthouses, foundries and remelters with alkali-sensitive alloys.
Rolling slab casthouses
Aluminum-magnesium alloys for sheet and plate, where sodium at a few ppm causes edge cracking in hot rolling.
- Low-sodium specification
- Grade matched to furnace
- Batch COA
Rotary flux injection
Granular MgCl₂-based salt fed through a rotor as a replacement for chlorine gas.
- Injection-sized granules
- Low fines
- Feeder compatibility checked
Foundry Al-Si alloys
Calcium control in aluminum-silicon casting alloys, where calcium is cited as harmful above about 150 ppm.
- Grade matched to alloy
- Dosing guide supplied
- Batch traceability
After sodium modification
Removing residual sodium when an alloy line switches away from sodium-modified product.
- Alloy reviewed before quoting
- Trial packs available
- Technical desk review
Moving off chlorine
Plants replacing chlorine fluxing to cut emissions and chlorine handling.
- Like-for-like comparison
- Composition data for permits
- SDS with every batch
Scheduled supply
Melt treatment runs every shift, so steady call-off supply matters more than spot price.
- Annual contracts with call-off
- Price held across the contract
- Second source held in reserve
Delivered to US plants and ports
We ship alkali remover to nominated delivery points across the United States. The regions below are destinations we serve — Chelora Chemicals is a sourcing and supply partner, not a US manufacturer, and does not hold US stock.
Gulf Coast
The largest US chemical cluster, and the usual entry point for bulk consignments.
- Houston & Galveston, TX
- New Orleans & Baton Rouge, LA
- Mobile, AL
Northeast
Container and bulk delivery into the mid-Atlantic and New England manufacturing belt.
- Newark & Elizabeth, NJ
- Philadelphia, PA
- Boston, MA
Southeast
Port-side delivery for the Carolinas, Georgia and Florida processing plants.
- Savannah, GA
- Charleston, SC
- Jacksonville, FL & Norfolk, VA
Midwest & Great Lakes
Inland rail and truck forwarding from the nearest coastal port to the industrial Midwest.
- Chicago, IL
- Detroit, MI
- Cleveland & Columbus, OH
West Coast
Pacific routing for West Coast processors and formulators.
- Los Angeles & Long Beach, CA
- Oakland, CA
- Seattle & Tacoma, WA
Southwest & Mountain
Inland delivery to interior states, forwarded from the Gulf or Pacific gateway.
- Dallas–Fort Worth, TX
- Phoenix, AZ
- Denver, CO
Importing into the United States
An alkali remover flux is a chemical mixture, so TSCA looks at each component rather than the product name. Under TSCA section 13 the importer of record, or its authorized agent, must certify to US Customs and Border Protection that each shipment either complies with TSCA or is not subject to it. We confirm the Inventory status of every component with the producer and agree in writing who files that certification before the first consignment moves.
Which party carries that duty follows the Incoterm. On FOB, CFR or CIF terms it is usually the US buyer; on DDP terms it can be the seller or its agent. Safety data sheets and labels are supplied to OSHA's updated Hazard Communication Standard, and the grade-specific transport transport documentation is prepared before booking.
| Item | How it works |
|---|---|
| Delivery points | Any nominated US plant, terminal or port of discharge |
| Incoterms quoted | FOB · CFR · CIF · DDP |
| Importer of record | Agreed in writing before the first shipment |
| TSCA certification | Section 13 positive certification filed at entry |
| Documentation | Batch COA, SDS, packing list, certificate of origin |
| Pack formats | Sealed bags or drums; fused-block grades boxed |
Note: regional coverage describes where we deliver, not where we hold inventory. Lead time depends on producer scheduling and ocean transit to your nominated US port — we confirm both in the quotation.
How we supply alkali remover
Chelora Chemicals is an alkali remover supplier and sourcing partner, not a manufacturer. We place your order with a qualified producer whose grade fits your alloy and how you introduce the flux.
The application method decides the form. Fused blocks suit plunging with a graphite bell; granules suit rotary flux injection and need a controlled size and low fines. Tell us your equipment and we will specify accordingly.
The other thing we will press on is packaging. Magnesium chloride takes up water readily, and hydrated flux releases HCl when heated and loses its effect. Moisture-barrier packing and quick use after opening are not optional on this product.
- Form matched to your equipment. Blocks for plunging, granules for rotary injection.
- Removes alkalis without losing magnesium. MgCl₂-based grades for Al-Mg alloys.
- Moisture-barrier packaging as standard. Hydrated MgCl₂ releases HCl and stops working.
- Composition data for your air permit. Supplied with the grade.
- Trial packs before a contract. Measure sodium and calcium before and after on your own melt.
- Batch traceability to the producing plant. Full chain of custody documentation on request.
Sealed tight against moisture
Moisture-barrier bags, lined drums or boxed fused blocks, with full documentation.
Moisture-barrier bags
Heavy-duty sealed bags for granular and powder grades.
Sealed lined drums
Lined drums with tight closures for use at the furnace.
Boxed blocks
Cast blocks for plunging, boxed and sealed.
Bulk bags
Lined bulk bags for high-volume rotary injection, subject to moisture controls.
Incoterms to suit you
Quoted on the Incoterm your purchasing team works to.
Small trial quantities
Small packs for trial on your alloy before a commercial order.
Chloride salt, water and molten metal
An alkali remover is a chloride salt flux, and its defining hazard is moisture. Hydrated magnesium chloride decomposes on heating to hydrogen chloride and magnesium oxide, and any water reaching molten aluminum can cause a violent steam eruption. Fume is evolved at the melt. The summary below is orientation only; the safety data sheet supplied with your batch is the authoritative document.
Classified hazards
Cl⁻Chloride salt base: irritating to eyes, skin and respiratory tract.HClHydrated MgCl₂ releases hydrogen chloride when heated.FumeFume evolved at the melt: use local exhaust ventilation.H₂ODamp flux on molten aluminum: risk of violent steam eruption.SDSGrade-specific GHS classification in the batch SDS.
The US air rule worth knowing. EPA's secondary aluminum NESHAP, 40 CFR Part 63 Subpart RRR, defines reactive fluxing as any gas, liquid or solid flux, other than cover flux, that results in a hazardous air pollutant emission, and it defines cover flux as salt added to the melt surface without surface agitation to prevent oxidation. Foundries, die casters and extruders melting only clean charge, customer returns or internal scrap are outside the definition of a secondary aluminum production facility. Whether your fluxing practice brings you inside the rule is a determination for you and your permitting authority; we supply the composition data you need to make it.
Storage
Store in sealed original packaging in a dry, covered area, off the floor and away from food and feedstuffs. Magnesium chloride is strongly hygroscopic: open containers only when needed and use part-opened packs promptly. Flux that has absorbed moisture should not be used.
Handling
Handle with gloves, eye protection and dust control, and apply only with dry, preheated tools. Never add damp or cold material to a melt. Fumes evolve at melt temperature, so furnace-side local exhaust ventilation is appropriate. Follow the exposure controls set out in the batch SDS and your own foundry safety program.
Transport
Most chloride-based fluxes ship as non-dangerous goods, but that is a grade-level question, not a product-name one: fluoride content can bring a formulation into a toxic or environmentally hazardous class. We confirm and document the classification for your specific grade, packaging and destination before booking.
Every batch, documented
We verify documentation before dispatch so there are no surprises at your incoming-goods bench.
Specification agreed
Alloy family, melt temperature, application method and the grade chemistry confirmed against your process before the order is placed.
Producer batch testing
The producing plant tests each batch against the agreed specification before release.
Documentation review
COA, SDS, TSCA position and transport classification checked by our desk before the shipment is booked.
Traceable dispatch
Each shipment is traceable to its producing batch, with full chain-of-custody records on request.
Why a few ppm matter so much
Sodium is a strange impurity: almost insoluble in solid aluminum, and harmful at levels most specifications would round to zero. In aluminum-magnesium alloys, sodium at 5 to 10 ppm is enough to considerably reduce hot rollability, causing edge cracking in slabs. Calcium does its own damage in aluminum-silicon alloys, where levels above about 150 ppm are cited as harmful.
The traditional answers were chlorine fluxing and fluoride fluxes. Both remove sodium and calcium, and both also remove magnesium, as magnesium chloride or magnesium fluoride, which is exactly the element an aluminum-magnesium alloy is trying to keep. Chlorine adds handling and emissions problems of its own.
A magnesium chloride based flux turns that around. Sodium and calcium take the chlorine; the magnesium goes into the metal. Fed as granules through a rotor, it has become a common replacement for chlorine gas — on condition that it is kept dry, because hydrated magnesium chloride gives off HCl and loses its effect.
We do not publish operating process parameters here; this is background only. Full technical documentation accompanies every shipment, and any process-specific detail you need is best confirmed directly with our technical desk.
| Product family | Aluminum refining flux |
|---|---|
| Removes | Sodium, calcium and other alkalis |
| Typical base | MgCl₂–KCl |
| Key reaction | MgCl₂ + 2Na → 2NaCl + Mg |
| Magnesium | Retained in the melt |
| Application | Plunged, injected or rotary |
Related foundry & melt-treatment products
Other aluminum melt-treatment inputs supplied from the same desk.
Alkali remover, answered
What does an alkali remover do?
Why remove sodium and calcium from aluminum?
Where do the alkalis come from?
What is an alkali remover made of?
Does an alkali remover take out magnesium too?
How is an alkali remover applied?
Why must it be kept dry?
Is alkali removal covered by EPA rules?
What safety precautions apply?
Do you manufacture alkali remover?
Get a quote on alkali remover
Tell us your alloy, your sodium and calcium levels and targets, and how you introduce flux today. We will match a grade and form to your equipment and quote a trial pack so you can measure the result.