Small Gold Wash Plant: Prices, Sizing and Water Needs

Small gold wash plant: the short answer

A small gold wash plant is a portable machine that screens gravel, breaks up clay and runs the fine material over a sluice so the gold settles out. In wash plant mining at small scale, the common sizes handle roughly 7 to 70 tons of gravel an hour. One US maker, Heckler Fabrication, lists trommel plants with sluice boxes from US$5,790 for a 7+ ton per hour mini trommel to US$63,175 for a 70+ ton per hour model (prices seen on its website in October 2026). The plant is rarely the biggest cost. Water, digging capacity, fuel, permits and, above all, how much gold your ground holds decide whether it pays.

This guide is for people who are sizing, buying or advising on a mini or small-scale plant: claim owners, small operators and the consultants who check their plans. It covers the parts of a plant, shaker versus trommel, a price and capacity comparison from one maker’s published list, water demand, settling ponds, how to size a plant from test pits, the questions to ask a seller, and a calculator that turns your own sample results into a daily estimate.

If you only need a hand sluice or a highbanker for a creek, read our guides on how to use a sluice box and the best sluice boxes for gold prospecting. A wash plant is the next step up: a machine fed by a loader or excavator rather than a shovel.

What is a wash plant in mining?

A wash plant is the processing unit at a placer mine. Placer gold is loose gold in sand and gravel, left by rivers or old stream channels, as opposed to lode gold still locked in hard rock. Because the gold is already loose, a placer operation does not need crushing or chemicals. It needs a way to wash a lot of gravel quickly and let gravity separate the heavy gold from the light sand.

The Alaska Placer Mining 101 Guidebook (BLM and partners, 2026) splits a plant into two jobs. Classification equipment removes boulders and oversize rock; the recovery plant then catches the gold. Sluice boxes remain by far the most common recovery equipment in Alaska, the guidebook says, because they have no moving parts, cost relatively little and need little maintenance.

A typical small plant has these parts:

• Feed hopper, often with a grizzly (steeply sloped steel bars) on top to stop boulders.
• Classifier: a vibrating shaker screen or a rotating trommel drum, with spray bars that wash the gravel.
• Sluice box with riffles, expanded metal and matting to trap gold; larger plants may add a jig or centrifuge for fine gold.
• Water pump and engine or electric motor.
• Frame, skid or trailer so the plant can be moved between cuts.
• Tailings and water handling: a discharge chute, settling ponds and sometimes a sand screw.

The same layout scales from a trailer plant behind a pickup to a production plant fed by trucks. “Small” here means plants a one- or two-person crew can run with one loader or excavator.

▶ How gold goes from rock to ring, step by step, including where gravity recovery fits. · 5:27

Shaker plant or trommel plant

The classifier is the main design choice, and it depends on your gravel, not on brochures. The BLM Alaska guidebook gives the trade-off plainly. Shaker screens use vibration and spray bars, and screen decks can generally process larger quantities of material than trommels. Trommels are rotating screen drums; they classify less material for their size, but they are excellent at breaking up clay and compacted or cemented gravel.

Infographic

How gravel moves through a small wash plant

1. 1GrizzlySteel bars reject boulders at the hopper.
2. 2ClassifyShaker screen or trommel washes and sizes the gravel.
3. 3SluiceRiffles and matting trap gold from the fines.
4. 4Fine goldOptional jig or centrifuge catches the smallest gold.
5. 5PondsSettling ponds clear the water for recycling.

That matters because clay balls can pick up gold and carry it off the end of the plant onto the oversize pile. If your test pits show sticky clay, a trommel with a scrubber section (the solid part of the drum where gravel tumbles before it reaches the screen) is the safer choice. Clean, loose, fast-draining gravel suits a shaker, which usually moves more material per hour for the same size.

The guidebook also describes derockers, a Yukon design with a moving deck of slats that rolls off boulders. They handle bouldery ground but classify less precisely and have more moving parts to maintain.

Small gold wash plant prices and capacity

Few makers publish prices, so a dated list from one maker is a useful yardstick rather than a market average. Heckler Fabrication, a US builder of trommel plants, lists the gold-recovery versions (with a sluice box) below. Prices are the base gold-recovery price shown on each product page in October 2026 (gas engine where offered; the 4815 is diesel or electric only); other drive options, longer barrels and jig options cost more.

Chart

Starting price of Heckler trommel wash plants with sluice

US$, base gold-recovery price (gas where offered), list price October 2026

Two patterns stand out. First, price per ton of rated capacity does not fall steadily with size: about US$830 per t/h for the mini, US$870 for the 2410, US$750 for the 3610 and US$900 for the 4815, with the Mini-Max (about US$1,280) and the 159 (about US$1,390) the most expensive per ton. Second, the small plants are light. The 159 trommel weighs about 2,400 lb (1,089 kg) on its trailer, so it can be towed to a site on a forest road; the 4815 at 9,000 lb needs a heavier truck and better access.

Ratings are maximums at full feed on suitable gravel. A “10+ ton per hour” plant fed by a small excavator on clay will often run well below that. Treat any rating as the top of the range and size around what your digging equipment can actually deliver.

Other costs to budget beside the plant: a loader or excavator (usually the largest item), a pump and suction line if not included, fuel, a generator for electric models, settling pond construction, spare screens, belts and pump seals, freight, and the reclamation bond or financial guarantee your regulator requires.

How much water a gold wash plant needs

Water is the constraint most buyers underestimate. Heckler’s pages give the minimum and preferred pump flow for each model, from 230 US gallons per minute (gpm) for the mini plants to 800+ gpm preferred for the 70 t/h plant. At 380 gpm the 159 trommel moves about 22,800 US gallons an hour, which is about 113 cubic yards of water for roughly 7 cubic yards of gravel.

Chart

Pump flow needed per wash plant model

US gallons per minute (minimum, or preferred where no minimum is given)

Few small sites have a stream that can supply that, and in most places you are not allowed to take it straight from one and send it back muddy. The answer is a recycle system: the plant draws from a clear pond, the dirty water flows to settling ponds, and the clarified water is pumped back. The BLM Alaska guidebook notes that Alaska DEC discharge permits require recycling of process water and only allow discharge of excess water. Ponds alone often cannot meet turbidity limits, it adds, so flocculants or filtration may be needed if you discharge at all. Do not site a pond so close to a stream that the channel can move into it.

A closed recycle circuit only needs start-up water to fill the ponds and make-up water to replace what soaks into the tailings and evaporates. Alaska’s Application for Permits to Mine in Alaska (APMA) asks for exactly these details: the number of recycle and settling ponds, start-up and make-up water, pump rates in gallons per minute, and cubic yards processed per day.

Recycling cleaner water also helps recovery: the BLM guidebook says that sand screws and hydrocyclones used with a recycle system can increase gold recoveries by returning cleaner water to the plant, and make tailings easier to handle.

How to size a gold wash plant for your ground

The rated capacity on a plant is the most material it can take at full feed. What you can actually process depends on your ground and your digging equipment. Work it out in this order.

1. Test the ground first. Dig test pits or trenches in rows (called fences) across the deposit and process measured samples from each with a pan or highbanker. Weigh the gold to get a grade: grams of gold per cubic yard or per tonne. Placer grades in the US are usually stated per bank cubic yard (BCY), the volume in the ground.
2. Allow for swell. Gravel loosens when dug. The BLM Alaska guidebook gives an average swell of about 14% for gravel, so 100,000 BCY becomes about 114,000 loose cubic yards (LCY), the volume your plant actually processes. Grade samples taken as loose material are already per LCY.
3. Match the plant to your excavator or loader. Time how many buckets your machine can dig and deliver in an hour and convert that to tons. A plant much larger than your digging rate sits idle; one much smaller becomes the bottleneck.
4. Look at the clay. Clay-rich gravel needs a trommel or scrubber; clean gravel can go over a shaker.
5. Check the gold size. Sieve your concentrate. If much of the gold is finer than about 0.1 mm, plan for matting designed for fines or a secondary jig or centrifuge.
6. Size the water supply and ponds at your planned feed rate, using the maker’s gpm figure.
7. Check permits before you buy. Placer mining, water use and discharge rules are set by state, province or country. A plant you cannot legally run is dead money.

Core and trench sampling is its own discipline; our guide to core samples covers how samples are logged, and an independent lab can confirm gold purity once you have concentrate.

How much gold a small wash plant can recover

A wash plant only concentrates what is in the gravel, and recovery depends heavily on gold size. In a 2021 British Geological Survey paper on artisanal mining in Kenya, Mitchell and co-authors note that a well-operated sluice box can recover over 95% of 1 mm gold particles, but less than 20% of gold finer than 0.1 mm (100 microns). The same paper says a shaking table, a gravity method suited to fine gold, can recover gold as fine as 15 microns.

Chart

Gold price, quarterly average

US$ per troy ounce

The BGS handbook on large sluice boxes (CR/02/029N) makes the practical points: classify the feed, keep the slurry mostly water, and clean up before the riffles pack with black sand. Every wash plant’s sluice follows the same rules as a hand sluice, just at higher flow.

The economics then come down to a simple sum: loose cubic yards per day times grams per yard times recovery times the gold price, minus fuel, labour, equipment and reclamation. For a dated reference point, the World Bank Pink Sheet (October 2026) gives a gold average of US$4,319 per troy ounce for September 2026, about US$139 per gram. Payable gold is lower than that: placer gold is an alloy, often containing silver, and refiners pay on the fine gold content less their charges. Use the calculator above with your own numbers and today’s price. Our article on mining profitability covers the wider cost picture.

What to ask a seller before buying a gold wash plant

Whether the plant is new or used, ask the seller these questions and get the answers in writing.

• What feed rate was the rating measured at, and on what material? A capacity quoted on clean sand will not hold on clay-rich gravel.
• What is the smallest gold the sluice is designed to catch? Fine gold washes over simple riffles. Ask what mats, riffles or concentrators are fitted and whether you can see test results.
• How much water and power does it need at full feed? Compare the answer with your pump, generator and water source.
• What is the screen size? Coarser screens send more rock over the sluice and make fine gold harder to catch.
• How is it moved? Check the weight, whether it is skid- or trailer-mounted, and whether it can reach your site by road.
• Where do spare parts come from? Screens, pump seals and belts wear out. A cheap plant with parts shipped from overseas can cost weeks of downtime in a short season.
• For a used plant: ask for its hours, the ground it ran on, and a chance to see it run with material.

Price only makes sense after these answers. Compare quotes for plants with the same capacity, sluice design and delivery terms, and check whether freight, pump and hoses are included.

Wash plant maintenance in the field

Most lost production on small plants comes from simple wear. The BLM guidebook points out that a grizzly is the cheapest way to stop boulders wiping out spray bars or jamming the hopper, and that boulders piling up beside it must be cleared regularly. A short daily routine helps:

• Check spray nozzles for blockage and wear; uneven spray leaves clay unwashed.
• Inspect screen panels or punch plate for holes that let oversize reach the sluice.
• Check belts, chains or drive rollers, bearings and grease points on trommels.
• Watch the sluice: if black sand reaches the lower riffles, clean up sooner and lower the feed rate.
• Check pump intake screens and keep the intake in clear water, not in the settling pond’s sediment.
• Store fuel well away from water; the BLM guidebook recommends at least 100 feet from naturally occurring water bodies as a best practice.

Keep a log of hours, feed and gold recovered per clean-up. It becomes the best evidence for your own recovery rate, and lenders or partners will ask for it.

Permits and safety for small placer plants

Rules differ by place, but the same themes recur: the right to mine (a claim, lease or licence), landowner permission where surface and mineral rights are split, water use, discharge, fish and wildlife, and reclamation. In Alaska, the APMA sets a bonding threshold of five or more acres disturbed or 50,000 cubic yards a year. In Oregon, the DEQ’s 700-PM general permit covers only in-water placer mining, such as small suction dredges and non-motorized gear; other placer discharges to surface water are not authorised under it, so an upland wash plant needs a different route. In California, claim status and county rules matter as much as federal law; see our California claims compliance guide.

Never use mercury. The US EPA describes methods that avoid mercury for small-scale gold mining and notes that the Minamata Convention calls on nations to reduce, and where feasible eliminate, mercury use in the sector. A well-run wash plant with good concentrating equipment is part of that answer.

Applications beyond gold

The same gravity equipment works on other heavy minerals in gravel. Heckler offers its trommels with a jig instead of a sluice for diamond and gemstone recovery, and alluvial tin (cassiterite) is also recovered by gravity. Our guides to gravity separation methods and separating gold from ore compare jigs, spirals, shaking tables and centrifuges in more depth.

Finding ground worth washing

The plant cannot make up for poor ground, so where to dig matters more than which machine to buy. Satellite imagery helps consultants and claim owners screen ground before test pitting: mapping old channels, terraces, existing workings and access, and checking where settling ponds can sit away from streams. Farmonaut maps mineral prospectivity from satellite data for licence and claim owners; see an alluvial gold case study from Kenya. Its platform also covers fleet tracking, carbon footprinting, traceability, satellite verification for lenders and insurers and a satellite and weather API.

▶ How satellites help find gold by mapping the rocks and alteration around it. · 4:25

Frequently asked questions

What is a wash plant in mining?

It is the processing unit at a placer mine: it screens and washes gravel, removes oversize rock and runs the fine material over a sluice or other gravity device so the gold settles out.

How much does a small gold wash plant cost?

One US maker lists trommel plants with sluice boxes from US$5,790 (7+ t/h) to US$63,175 (70+ t/h), base gold-recovery versions, on its website in October 2026. Excavator, pumps, freight and ponds are extra.

What size wash plant do I need?

Size it to your digging rate and water supply, not the brochure. Time your excavator or loader in tons per hour, then choose a plant rated a little above that.

Is a trommel or a shaker better for gold?

Trommels break up clay and cemented gravel better; shaker screens usually process more clean gravel for their size, according to the BLM Alaska Placer Mining 101 Guidebook.

How much water does a mini gold wash plant use?

Small trommels listed by Heckler need at least 230 US gallons per minute, rising to 380 gpm for a 10 t/h plant. Most operations recycle water through settling ponds.

Can a small wash plant catch fine gold?

Only partly. BGS researchers report sluices recover over 95% of 1 mm gold but under 20% of gold finer than 0.1 mm, so fine-gold ground needs better matting or a centrifuge or jig.

How many cubic yards can a small wash plant process a day?

Multiply the real feed rate by operating hours. A 10 t/h plant running 8 hours is about 80 tons; weigh a measured loose yard of your own gravel to convert tons to cubic yards.

Do I need a permit to run a gold wash plant?

Almost always. Expect a mining right, water use and discharge rules, and reclamation or bonding. Check with the state, province or national regulator before buying.

Can a gold wash plant be used in Africa?

Yes, the same gravity equipment works on alluvial gold anywhere. Check the licence type, water and discharge rules and local spare-part supply first, and use gravity concentrators rather than mercury.

Is a small gold wash plant a good investment?

Only if test pits show enough gold. Payback depends on grade, recovery, running costs and the gold price; run the calculator with your own sample results.