Spent Sulphuric Acid Used / Recovered H₂SO₄
Chelora Chemicals sources and supplies Spent Sulphuric Acid — used sulfuric acid recovered from industrial processes such as alkylation units and metal pickling lines — as a lower-cost acid feedstock for fertiliser production, acid-regeneration plants, and neutralisation duties where some variability in composition is acceptable. Every lot is sold against its own assay, not a fixed generic specification.
Also known as: Used sulfuric acid, waste sulfuric acid, recovered H₂SO₄, spent acid
Request a quotation
Tell us the strength range and end use you need, and we will source a matching lot with price, lead time and a sample assay — usually within one working day.
Request a Quote Email the DeskDocumentation
- Lot-specific assay (strength, iron, organics, metals)
- Safety Data Sheet (SDS)
- Dangerous-goods transport documents, confirmed to your SDS
- Source-stream declaration, where required by destination rules
- Certificate of origin
What is Spent Sulphuric Acid?
Spent Sulphuric Acid is used or by-product sulfuric acid recovered from an industrial process rather than produced as a fresh, virgin-grade chemical. The underlying substance is sulfuric acid, H₂SO₄, but because it has already done a job — most commonly as a catalyst in refinery alkylation units, or as a pickling/processing acid elsewhere — its strength and the contaminants it carries depend entirely on where it came from.
This is a trading and recycling product, not a fixed-specification chemical: we source it from industrial off-take streams, have it assayed, and match lots to buyers who can use that specific strength and contaminant profile — typically fertiliser producers, acid-regeneration plants, and processors that can accept some variability in exchange for a lower price than virgin sulfuric acid.
Handling follows standard precautions for a strong corrosive acid — acid-resistant gloves and face/eye protection, adequate ventilation, and storage in acid-rated containers — with the added note that contact with many metals can release flammable hydrogen gas, and that composition should always be confirmed against the specific lot's assay before use.
Why buy Spent Sulphuric Acid specifically
- Lower cost than virgin acid. Because it is a recovered material rather than freshly manufactured, it is typically priced well below virgin sulfuric acid of comparable strength.
- A genuine use for a by-product stream. Buying spent acid gives refineries, pickling lines and other generators a route to recover value from a stream that would otherwise need disposal or treatment.
- Good fit for tolerant end uses. Fertiliser manufacture, acid regeneration and bulk neutralisation applications can absorb the natural variability in a recovered acid stream in a way a sensitive chemical process cannot.
- Not a substitute for virgin acid in sensitive uses. Where consistent, contaminant-free sulfuric acid is required (battery acid, food/pharma-grade uses), buy virgin-grade sulfuric acid instead — spent acid is priced and sold for a different set of applications.
Where Spent Sulphuric Acid Comes From
Spent Sulphuric Acid is not manufactured to order — it is recovered, assayed, and matched to a buyer. The main source streams are:
- Refinery alkylation units. Sulfuric acid used as a catalyst in alkylation processes becomes diluted and picks up hydrocarbon residues over the course of the reaction, and is periodically drawn off as spent acid.
- Metal pickling and surface treatment. Sulfuric acid used to remove scale and oxide from metal surfaces accumulates dissolved metal salts and is replaced once it is no longer effective.
- Other acid-consuming chemical processes. Various chemical manufacturing processes that use sulfuric acid as a reagent or drying agent generate spent acid as a by-product stream.
- Assay and lot matching. Each recovered lot is assayed for strength and key contaminants (metals, organics, colour) and matched to a buyer whose process can accept that specific profile.
Typical Strength Range — Not a Fixed Specification
Because this is a recovered material, the figures below are a representative range across the lots we typically source, not a guaranteed specification. Every shipment is sold against its own lot assay.
| Parameter | Typical range |
|---|---|
| Appearance | Colourless to dark brown oily liquid, depending on source stream |
| H₂SO₄ strength | Commonly below 80% — confirmed per lot by titration |
| Metals content | Variable by source — reported per lot, important for sensitive buyers |
| Organic content / colour | Variable by source — particularly relevant for alkylation-derived lots |
| Water content | Balance of the lot assay |
Physical & Chemical Properties
| Property | Typical value |
|---|---|
| Chemical basis | H₂SO₄ in water, variable strength, plus source-dependent contaminants |
| Appearance | Colourless to dark brown, oily liquid, essentially odourless |
| Specific gravity | Around 1.3 – 1.4, varying with strength |
| Boiling point | Around 100 °C for dilute lots, rising with concentration |
| Water solubility | Miscible |
| Flammability | Not flammable; contact with many metals releases flammable hydrogen gas |
| Reactivity | Reacts exothermically with water at higher strengths; attacks many metals; neutralise with limestone, lime or soda ash |
Behaviour in the process
- Strong acid, variable purity. Delivers the acidity of sulfuric acid at a lower cost, with the trade-off of lot-to-lot variability in trace composition.
- Corrosive to common materials. Attacks carbon steel and many metals; handling equipment should be rated for sulfuric acid service.
- Heat on dilution. Mixing with water at higher strengths is exothermic — acid is added to water, never the reverse.
- Source-dependent colour and odour. Alkylation-derived lots are typically darker and may carry a hydrocarbon odour; pickling-derived lots typically carry dissolved metal salts instead.
Spent Sulphuric Acid and Related Industrial Acids
The right acid for your process depends on whether you need guaranteed purity or can trade some variability for a lower price.
| Acid | Character | When it is the right choice |
|---|---|---|
| Spent Sulphuric Acid | Strong, sulphate-based, recovered/variable grade | Fertiliser feedstock, acid regeneration, bulk neutralisation — cost-sensitive, tolerant processes |
| Virgin Sulphuric Acid | Strong, consistent, guaranteed specification | Battery acid, sensitive chemical manufacturing, any process needing guaranteed purity |
| Hydrochloric Acid | Strong, non-oxidising, chloride-based | Pickling, descaling, pH control — where sulphate residues are undesirable |
| Nitric Acid | Strong, oxidising | Metal passivation, nitration chemistry and processes needing an oxidising acid |
Stated plainly: if your process can tolerate variable trace composition and you want the lowest cost per tonne of acidity, Spent Sulphuric Acid is worth sourcing — if you need a guaranteed specification, our Hydrochloric Acid or a virgin sulfuric acid grade is the right call instead.
Industries We Supply Spent Sulphuric Acid To
Where Spent Sulphuric Acid is Used
Matching the lot to the buyer
The single most important step in this product is matching a lot's actual assay to a use that can accept it — an alkylation-derived lot with hydrocarbon carryover suits a different buyer than a pickling-derived lot carrying dissolved metals. Tell us your tolerance for strength and contaminants and we will source accordingly.
Need a lot matched to your process?
Tell us your acceptable strength range, contaminant tolerance, the packing format you can receive and the annual quantity. We will come back with a price, a lead time and a sample lot assay.
Assay & Lot Qualification
Because this product is recovered rather than manufactured to spec, every lot is assayed individually, and we recommend qualifying the first lot from any new source stream against your own process before committing to repeat volumes.
- H₂SO₄ strength — by titration, the primary measure for every lot.
- Metals content — reported because dissolved metals vary significantly by source stream and matter to sensitive buyers.
- Organic content / colour — particularly relevant for alkylation-derived lots carrying hydrocarbon residues.
- Source stream — disclosed where it affects suitability for your process or is required by destination regulations.
Common Issues & Likely Causes
| Symptom | Likely cause | What to check |
|---|---|---|
| Weaker acidity than expected | Strength below the assumed range for this lot | Titration result on the lot assay |
| Discolouration or odour in the receiving process | Organic/hydrocarbon carryover from an alkylation-derived lot | Source stream and organic content on the assay |
| Unexpected metal contamination downstream | Dissolved metals from a pickling-derived lot | Metals content on the assay |
Packaging, Storage & Shipping
- Standard packing. Tank trucks, ISO tanks and bulk tanker shipments are typical for this product given the volumes generally involved; drummed quantities are arranged where appropriate.
- Material compatibility. Store and handle in acid-rated containers — suitable corrosion-resistant alloy, rubber-lined or acid-resistant plastic. Avoid contact with most metals, which releases flammable hydrogen gas.
- Dilution direction. Where dilution is required, acid is always added to water, never the reverse, given the heat released.
- Transport classification. UN 1832, "SULPHURIC ACID, SPENT", Class 8, Packing Group II.
- Waste/by-product paperwork. Depending on the destination jurisdiction, a cross-border shipment of spent acid may fall under additional hazardous-material movement rules beyond standard dangerous-goods transport — confirm with your compliance team before the first shipment on a new lane.
Hazards & Safe Handling
Spent Sulphuric Acid is corrosive to skin and eyes, causing severe burns on contact, and is harmful if swallowed. It is also harmful to aquatic life at very low concentrations. Source-dependent contaminants (metals, organics) may add further hazards specific to a given lot — always refer to that lot's own SDS.
- Skin and eye contact. Acid-resistant gloves, chemical goggles and a face shield are standard practice; flush thoroughly with large amounts of water for at least 15 minutes and seek medical attention.
- Ingestion. Do not induce vomiting; seek immediate medical attention.
- PPE. Chemical goggles, face shield, acid-resistant gloves, boots and apron.
- Metal contact. Reaction with many metals generates flammable hydrogen gas — keep away from ignition sources where metal contact is possible.
- Environment. Notify local water-intake operators and environmental agencies in the event of a release; neutralise spills with limestone, lime or soda ash.
Regulatory & Compliance Notes
Because Spent Sulphuric Acid is a recovered by-product rather than a defined pure chemical, its regulatory treatment varies more by jurisdiction than a virgin chemical's would. The notes below are orientation rather than legal advice.
- Classification as waste vs. recoverable material. Some jurisdictions classify spent acid as a hazardous waste or recyclable material requiring specific permits or transboundary-movement notifications (for example under Basel Convention-aligned controls), even when it is being sold for genuine reuse rather than disposed of. Confirm the classification that applies at both the origin and destination before shipping.
- Dangerous goods transport. UN 1832, Class 8, Packing Group II — confirmed and consistent across the dangerous-goods codes we checked.
- HS / customs classification. This is the item most likely to need a customs-broker decision rather than a lookup: depending on your jurisdiction, it may be classified under the sulfuric acid heading or under a chemical-industry-waste/residue heading. Confirm with your broker for each destination before publishing a fixed HS code in your own documentation.
- End-use declaration. Some buyers' import permits require a declared end use (e.g. fertiliser feedstock, acid regeneration) — confirm what your destination market requires before the first shipment.
We Source & Supply Spent Sulphuric Acid Across All Seven Continents
Chelora Chemicals sources spent acid from industrial generators and matches it to buyers across every inhabited continent, handling the export documentation, assay and freight so the material arrives ready for the receiving process.
- Incoterms. EXW, FOB, CIF, CFR and DAP quoted to suit your purchasing terms and freight arrangements.
- Ports. Regular shipments through Nhava Sheva (JNPT) and Mundra, with other ports arranged as routing allows.
- Documentation. Commercial invoice, packing list, lot assay, SDS and any required waste-movement paperwork issued as a complete set.
- Flexible volumes. From trial tanker loads up to repeat bulk shipments on a supply contract.
Buying Spent Sulphuric Acid from Chelora
We are an independent sourcing partner for this material. Because it is recovered rather than manufactured to spec, that means settling three things at enquiry: the strength range and contaminant tolerance your process can accept, the packing/transport format, and the quantity you need.
- Documentation on every lot. Lot-specific assay with strength and contaminant profile, plus the current SDS.
- Analysis before commitment. Representative analysis from the actual lot shared ahead of a commercial order so your lab can qualify it.
- Quantities. Trial tanker loads through to repeat bulk shipments on contract supply.
- Inspection. Independent third-party inspection available at loading when the contract requires it.
- Related acids. Hydrochloric Acid and other industrial acids alongside this product from one supplier.
How ordering works
- Send the enquiry. Acceptable strength range, contaminant tolerance, destination port and the Incoterm you buy on.
- We source and quote. We match an available lot and come back with price, lead time, packing format and a sample assay, normally within one working day.
- Qualify the lot. We share the actual lot assay so your technical team can sign off before you commit.
- Confirm transport and compliance classification. We work with you and your logistics/compliance team to confirm UN 1832 documentation and any waste-movement paperwork for your lane.
- Confirm the order. Proforma invoice issued; payment terms agreed against the volume and the relationship.
- Ship and document. Loaded with the full export document set, and tracked through to arrival.
Spent Sulphuric Acid — Common Questions
The questions our technical desk is asked most often about Spent Sulphuric Acid. If yours isn't here, call or email and you will reach someone who knows the material.
What exactly is Spent Sulphuric Acid?
It is used or by-product sulfuric acid (H₂SO₄) recovered from an industrial process — most commonly refinery alkylation units or metal pickling lines — rather than freshly manufactured. It is sold against its own lot assay rather than one fixed specification.
Is there a CAS number for this product?
The underlying substance is sulfuric acid, CAS 7664-93-9, but because "spent" material is a variable, recovered stream rather than a defined pure substance, it is not sold against that CAS number the way a virgin chemical would be. Each lot's own assay is what defines the material you receive.
What is Spent Sulphuric Acid used for?
Mainly as feedstock for fertiliser production (ammonium sulphate, SSP), as input to acid-regeneration plants that convert it back into virgin-grade acid, and in bulk neutralisation duties that can tolerate variable composition.
How does it differ from virgin sulfuric acid?
Virgin sulfuric acid is manufactured to a guaranteed specification. Spent Sulphuric Acid is recovered from a prior industrial use and carries variable strength and contaminants depending on its source, which is reflected in a lower price — it suits tolerant, high-volume applications rather than sensitive chemical processes.
Do you supply Spent Sulphuric Acid worldwide?
Yes. Chelora Chemicals sources and supplies Spent Sulphuric Acid across every inhabited continent — Asia, Europe, Africa, North America, South America, and Australia & Oceania — as well as throughout India.
Is Spent Sulphuric Acid hazardous?
Yes — it is corrosive to skin and eyes, causing severe burns, and is harmful if swallowed. Source-dependent contaminants may add further hazards specific to a given lot, so always refer to that lot's own SDS.
What is the UN number and transport classification?
UN 1832, "Sulphuric acid, spent", Class 8 (corrosive), Packing Group II — this is well and consistently documented. Some destinations may apply additional hazardous-waste or recyclable-material movement rules on top of the standard dangerous-goods paperwork; confirm this with your compliance team.
What strength will I receive?
Strength varies by lot and is confirmed by titration on each specific shipment — commonly below 80% H₂SO₄, but always sold against that lot's own assay rather than a fixed number. Tell us your acceptable range and we will match a suitable lot.
How should Spent Sulphuric Acid be stored?
In acid-rated containers suitable for sulfuric acid service, away from most metals (which release flammable hydrogen gas on contact) and other incompatible materials. If dilution is required, acid is always added to water, never the reverse.
What packing and order quantities are available?
Tank trucks, ISO tanks and bulk tanker shipments are typical given the volumes usually involved in this product; drummed quantities can be arranged where appropriate. Orders run from trial tanker loads up to repeat bulk shipments on contract.
Looking for a Spent Sulphuric Acid source?
Tell us your acceptable strength range, contaminant tolerance and annual volume. We will match you with a lot, send you the actual assay, and quote a price and lead time — delivered anywhere in the world.