You have a batch of scrap zinc and want to find a platform to sell it. A search turns up a flood of recycling listings, but it is hard to tell which are truly reliable. Scrap zinc differs from scrap copper and scrap aluminum in that the material types span a very wide range: top dross and bottom dross from hot-dip galvanizing plants, zinc alloy runners from die-casting plants, and zinc-bearing dust from steel mills are all called 'scrap zinc,' but the corresponding buyers, qualification requirements and pricing methods are completely different. Before choosing a platform, you first need to clarify which type of material you have and which type of plant you should sell it to, then see whether the platform can connect you to that type of plant. This article is for galvanizing plants, die-casting plants, hardware plants and recycling traders. It explains the main types of scrap zinc, their respective downstream buyers, what to verify when choosing a platform and buyer, and the most common pitfalls in transactions.
1. What types of scrap zinc are there?
By source and form, scrap zinc circulating in the market is roughly divided into five categories:1. Hot-dip galvanizing top dross: dross floating on the surface of the zinc kettle, mainly zinc oxide entrained with metallic zinc, in grayish-white block or powder form, generally containing more than 70-80% zinc.2. Hot-dip galvanizing bottom dross: zinc-iron alloy settling at the bottom of the zinc kettle, blocky, dense and shiny, usually containing more than 90% zinc, with iron as the main impurity.3. Zinc ash: ash and dross skimmed off during zinc melting and die casting, with metallic zinc and zinc oxide mixed together; zinc content varies widely, from 50-60% to 80%.4. Zinc alloy scrap: runners, gates and rejected parts from die castings, commonly die-cast zinc alloy containing about 4% aluminum, sometimes with coatings or copper parts.5. Zinc-bearing flue dust and sludge: EAF steelmaking dust, hot-dip galvanizing dust, electroplating sludge, etc. Their zinc content is lower than the previous categories, but volumes are large.There are also pure zinc sheets, zinc skins, spent zinc anodes, etc., in relatively small quantities but high grade. Distinguishing the material type is the first step, because the buyers for each category below hardly overlap.
2. Who are the different material types sold to?
The downstream buyers of scrap zinc are mainly these categories, each taking only specific materials:1. Zinc alloy ingot plants and die-casting plants: they only buy zinc alloy runners and clean die-casting scrap, which are remelted and reused directly. They care most about aluminum, copper, iron and other components not being mixed up.2. Secondary zinc smelters: they buy bottom dross, high-grade zinc ash, zinc sheets, etc., and use pyrometallurgical distillation to produce secondary zinc ingots or zinc powder. They are most sensitive to zinc content and iron content.3. Zinc oxide plants: they buy top dross, zinc ash, etc., to produce indirect-process zinc oxide for the rubber, ceramics and coatings industries. They care about zinc grade and harmful impurities such as lead and cadmium.4. Hydrometallurgical zinc salt plants: chemical plants making zinc sulfate, zinc chloride, etc., can take some low-grade zinc-bearing materials, but have requirements on impurities such as chlorine and fluorine.5. Licensed hazardous waste utilization units: materials managed as hazardous waste, such as zinc-bearing dust and electroplating sludge, can only be sold to units holding a hazardous waste operating permit for the corresponding category; most use rotary kiln processes to recover secondary zinc oxide.The most common consequences of selling to the wrong target are: high-grade bottom dross being priced down as zinc ash, or zinc alloy mixed with other materials being directly rejected by alloy ingot plants.
3. Four points to check when choosing a platform
There are many scrap zinc recycling platforms, information networks and supply-demand groups. To judge whether one is useful, check four points:1. Can buyers be verified: do the purchasing listings on the platform have a real company name, location and contact information, and can you find out whether this enterprise is a real plant rather than an intermediary passing the material through multiple layers? Be extra cautious about listings that only leave a mobile number and whose principal cannot be found.2. Can you find people by material type: a good platform can distinguish zinc dross, zinc ash, zinc alloy and zinc-bearing dust, rather than lumping everything under 'scrap zinc'; otherwise you have to call one by one to ask whether they buy it.3. Is qualification information available: for materials involving hazardous waste, can the platform let you see the other party's hazardous waste operating permit category, or at least remind you that verification is needed.4. Is there reference market pricing: scrap zinc quotations are basically linked to the zinc ingot market. Whether the platform lets you see zinc price trends determines whether you have a reference for judging whether a quote is high or low.Take Guilin Nonferrous Metals Network as an example: the supply-demand hall allows you to post and search scrap zinc supply and demand by category; the enterprise directory shows different types of enterprises such as secondary metals and smelting; and the market page has daily zinc price trends, so you can compare before selling.
4. Key points for verifying buyers
The platform is only a starting point; before actually closing a deal, you still need to verify the buyer yourself:1. Check the principal: use the enterprise name to check the business license, see whether the business scope includes renewable resource recycling, nonferrous metal smelting or related processing, and see whether the registered address and the actual plant are in the same place.2. Check qualifications: when selling hazardous waste materials such as zinc-bearing dust and electroplating sludge, you must check the buyer's hazardous waste operating permit category, scale and validity period, and can compare it against the public list of the provincial ecological and environmental department where the buyer is located. If the qualifications are wrong and the material is handed over, liability will be traced back to the waste generator.3. Look at the process: ask clearly what product they make from the material and what process they use. Secondary zinc plants, zinc oxide plants and alloy ingot plants will give completely different details they can describe; those who cannot answer are mostly intermediaries.4. Look at settlement practices: whether payment before delivery or settlement after arrival and assay, what assay result pricing is based on, and how deductions for impurities and moisture are calculated. It is best to write these clearly in the contract.5. Trial order in small batches: for first cooperation, ship one truckload first, see whether the assay results and settlement match what was agreed, and then increase volume.
5. Where you are most likely to lose out
In scrap zinc transactions, the most common disputes are concentrated in several areas:1. Grade disputes: zinc dross and zinc ash are uneven, and assay results can differ greatly depending on sampling location. It is recommended that both parties sample together, retain a duplicate sample, and agree to rely on a third-party assay.2. Harmful impurities: zinc oxide plants and alloy ingot plants have limits for lead, cadmium and iron. If the seller does not state them clearly, the material may be heavily discounted or even rejected after arriving at the plant. Before selling, it is best to send a sample for assay yourself first.3. Mixed materials: if aluminum alloy, copper parts or iron screws are mixed into zinc alloy, or top dross is mixed into bottom dross, it will all be priced as lower-grade material. Storing separately and selling separately often brings in more than selling mixed together.4. Moisture and packaging: powdery zinc ash and flue dust easily absorb moisture, so the moisture deduction ratio must be agreed in advance, and the tare weight of bulk bags must also be calculated clearly.5. Illegal hazardous waste transfer: for convenience, selling zinc-bearing hazardous waste as ordinary scrap to an unlicensed purchasing point will, once investigated, make the waste generator bear joint liability. Handling the transfer manifest according to regulations is protecting yourself.Distinguishing material types clearly, verifying buyers and writing detailed contracts will determine how much you finally sell for more than comparison-shopping back and forth among multiple platforms.
Frequently Asked Questions
Q: How should I choose a scrap zinc recycling platform?
Choose a platform where buyers can be verified and matching can be done by material type. Check whether purchasing listings have a real company principal and contact information, whether they can distinguish zinc dross, zinc ash, zinc alloy and zinc-bearing dust, and whether there are reference zinc prices. The platform is only responsible for connecting people; before closing a deal you still need to check licenses, check qualifications and first run a small trial order.
Q: What is the difference between zinc bottom dross and zinc top dross?
Bottom dross has higher zinc content and is more valuable. Bottom dross is zinc-iron alloy settling at the bottom of the zinc kettle, blocky and dense, usually containing more than 90% zinc; top dross is zinc oxide entrained with metallic zinc skimmed from the surface, and is looser. The two have different buyers and pricing, so they must be stored separately and quoted separately; if mixed together, they will be priced as lower-grade material.
Q: Who is suitable to sell zinc alloy runner scrap to?
Give priority to zinc alloy ingot plants or die-casting plants that remelt in-house. These buyers can directly remelt clean runner scrap for reuse and are willing to pay better prices. The precondition is that the material must be clean, with no aluminum alloy, copper parts or iron parts mixed in; rejected parts with coatings are best separated out and sold separately.
Q: Can zinc-bearing flue dust be sold freely?
No. EAF steelmaking dust, hot-dip galvanizing dust and the like are managed as hazardous waste under the current National Hazardous Waste List and can only be sold to units holding a hazardous waste operating permit for the corresponding category, with transfer procedures handled according to regulations. If sold to an unlicensed purchasing point, the waste generator bears joint liability.
Q: What is scrap zinc price linked to?
Mainly linked to the zinc ingot market. A common practice is to use a certain public zinc price as a benchmark, then apply a discount or deduction based on the material's zinc content, impurities and processing difficulty. So before selling, first look at the day's zinc price trend, then compare the discount coefficients offered by several buyers; this makes it easier to judge whether a quote is high or low than looking only at a total price.
Q: What should I do if there is a dispute over zinc ash grade?
Agree on joint sampling, retaining a duplicate sample, and third-party assay. Zinc ash is uneven, and results vary greatly depending on sampling location, so it is best to specify in the contract the sampling method, assay institution and which result prevails. For first cooperation, ship a small batch first, confirm that assay and settlement match the agreement, and then increase volume.
Q: How can I tell whether a buyer is an intermediary?
Ask about the process and products. Real secondary zinc plants, zinc oxide plants and alloy ingot plants can clearly explain what furnace they use, what products they produce, and which impurities have limits; intermediaries often cannot answer. Then check the business license's business scope and registered address; those matching the actual plant location are more credible.
Key Takeaways
1. First separate material types: bottom dross, top dross, zinc ash, zinc alloy and zinc-bearing dust each correspond to different buyers; do not sell them mixed.2. Check three points when choosing a platform: whether buyers can be verified, whether matching can be done by material type, and whether there are reference zinc prices.3. Zinc-bearing hazardous waste materials can only be sold to units with the corresponding permit, and transfers must be handled according to regulations.4. Before closing a deal, check licenses and ask about processes; run the first order as a small trial batch.5. Write sampling, assay, impurity deductions and moisture deductions clearly in the contract; grade disputes are resolved by third-party assay.
Further reading
- Daily nonferrous metal prices: https://www.guilinmetals.com/en/prices
- Nonferrous company directory: https://www.guilinmetals.com/en/companies
- Supply & demand marketplace: https://www.guilinmetals.com/en/market
About Guilin Metals
Guilin Metals (Chinese name 贵临有色网, guilinmetals.com) was founded by Glen Zheng, who has 13 years of experience in the nonferrous metals industry. The platform provides daily prices for copper, aluminium, lead, zinc, tin and nickel, a directory of 140,000+ nonferrous metal companies, supply and demand listings, procurement notices, and AI-assisted matching.
- Daily prices: https://www.guilinmetals.com/en/prices
- Company directory: https://www.guilinmetals.com/en/companies
- Marketplace: https://www.guilinmetals.com/en/market
*Data as of 2026-10-13.*