{"id":718,"date":"2025-02-26T06:24:45","date_gmt":"2025-02-26T06:24:45","guid":{"rendered":"https:\/\/lowayequipment.com\/?page_id=718"},"modified":"2026-10-24T14:35:49","modified_gmt":"2026-10-24T14:35:49","slug":"nonferrous-metallurgy","status":"publish","type":"page","link":"https:\/\/lowayequipment.com\/vi\/industry-applications\/nonferrous-metallurgy\/","title":{"rendered":"Nonferrous Metallurgy"},"content":{"rendered":"\t\t
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Industry Applications · Nonferrous Metallurgy<\/p>\n

Two Dewatering Lines Inside a Nonferrous Metallurgy Plant<\/h1>\n

One line carries metal. Leach residue, red mud and refinery slime arrive with pregnant liquor in their moisture, and that liquor is value walking out of the gate. The other line carries water. Neutralised effluent and plant sludge have to leave site as a cake, at a volume the plant actually produces every day. They are sized on different numbers, and only one of them is a belt press duty.<\/p>\n

\n Send us your duty<\/a>\n See the two lines<\/a>\n <\/div>\n <\/div>\n
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01<\/span>Value line · pressure filtration<\/div>\n
02<\/span>Water line · continuous sludge<\/div>\n
03<\/span>Cu · Zn · Ni · Co<\/div>\n
04<\/span>Al · Au · Ag<\/div>\n <\/div>\n<\/section>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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The split<\/p>\n

The value line and the water line are not the same job<\/h2>\n

One is measured in metal recovered. The other is measured in what leaves site and what the discharge permit allows. A machine sized for one of those targets is the wrong size for the other, which is why the split comes first and the equipment comes later.<\/p>\n

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The value line<\/h3>\n

Fine, compressible residue holding pregnant liquor. The cake has to be washed, the filtrate has to come back clean, and the cycle has to include a squeeze. This is batch pressure filtration on a hydrometallurgy filter press, run against a recovery target rather than a discharge limit.<\/p>\n

Leach residue · Red mud · Refinery slime · Concentrate<\/p>\n <\/div>\n

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The water line<\/h3>\n

Neutralised acid effluent and plant sludge. Flow is continuous, volume is large, and the cake has to leave site without dripping. Two of these sludges still land on a hydrometallurgy filter press; the dilute plant effluent is where a belt press belongs.<\/p>\n

Sulphide sludge · Neutralisation sludge · Gypsum · Plant effluent<\/p>\n <\/div>\n <\/div>\n

Most plants need both, and they are usually bought years apart. The hydrometallurgy filter press is sized on the residue; the belt press is sized on the flow.<\/p>\n <\/div>\n<\/section>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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The value line<\/p>\n

Leach, thicken, wash, dewater<\/h2>\n

A hydrometallurgy circuit moves metal from solid into liquor, then has to move it back out of the residue before the residue leaves. The order of those steps is fixed. What changes between plants is how many wash stages the target asks for, and a hydrometallurgy filter press is the station where that number is settled.<\/p>\n

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01<\/span>

Leach<\/h3>

Acid or caustic dissolves the value. What is left still holds liquor in its moisture.<\/p><\/div>\n

02<\/span>

Thicken<\/h3>

Solids are concentrated so the separation step receives a feed it can pump and fill.<\/p><\/div>\n

03<\/span>

Wash & dewater<\/h3>

A hydrometallurgy filter press fills, squeezes, pushes wash water through the cake and blows the core clear.<\/p><\/div>\n

04<\/span>

Filtrate<\/h3>

Pregnant liquor and wash water return to leach, to solvent extraction or to electrowinning.<\/p><\/div>\n

05<\/span>

Residue<\/h3>

A cake that can be hauled to a stack, or carried on to a smelter.<\/p><\/div>\n <\/div>\n

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\"Several<\/figure>\n

Everything ahead of a hydrometallurgy filter press prepares the feed. Everything behind it lives with the number it produced.<\/p>\n <\/div>\n <\/div>\n<\/section>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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The duties<\/p>\n

Four residues that have to be pressed<\/h2>\n

Each one reaches a hydrometallurgy filter press for a different reason, and each is sized from a different number. A single plant can hold all four at once.<\/p>\n

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01<\/span>Acid leach residue<\/h3>\n

Copper, zinc, nickel and cobalt circuits each leave one. The moisture in the cake is pregnant liquor, so a litre left in the residue is dissolved metal going to the stack. Filtration is judged on how dry the cake leaves and how much of the value reports back to the circuit, and on a hydrometallurgy filter press it is the wash rather than the squeeze that moves that second number.<\/p>\n <\/div>\n

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02<\/span>Bayer red mud<\/h3>\n

Alumina refining leaves a caustic, very fine residue at the largest tonnage of the four. Most particles sit below ten microns, so resistance to flow is high and the cake has to be built under pressure. The target is a stackable residue with the caustic kept out of the drainage. Units run in parallel with a spare on the line, because this hydrometallurgy filter press duty runs every shift.<\/p>\n <\/div>\n

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03<\/span>Precious metal slime<\/h3>\n

Gold and silver precipitate from refining arrives in small volumes at high value per tonne. The hydrometallurgy filter press cycle is tuned for capture rather than throughput: cloth that holds the fines, a wash that strips the mother liquor, and a cake that leaves the press whole instead of cracked on the way to the refinery.<\/p>\n <\/div>\n

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04<\/span>Concentrate<\/h3>\n

Where the dewatered solid is the product, moisture is shipped weight. Concentrate filtration is the plainest duty on this page: press it, dry it, load it. The hydrometallurgy filter press is still bought on cake moisture, just with a freight bill behind the number.<\/p>\n <\/div>\n <\/div>\n <\/div>\n<\/section>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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The water line<\/p>\n

One neutralisation plant, three different sludges<\/h2>\n

Lime neutralisation of acid effluent does not produce one sludge. Sulphide precipitate, metal hydroxide and gypsum settle differently, thicken to different densities and each asks a hydrometallurgy filter press or a belt press for something different.<\/p>\n

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\"Filter<\/figure>\n
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Sulphide sludge<\/h3>

Metal sulphide from a sulphide dosing step. It thickens to a thin slurry, so the hydrometallurgy filter press sees a large volume for a small dry tonnage. The cake has to be handleable and the filtrate goes back into the water circuit.<\/p><\/div>\n

Neutralisation sludge<\/h3>

Metal hydroxide from lime dosing, and the largest sludge volume on the site. Without flocculant ahead of the press the cake comes out firm enough to haul; with it, the same press runs faster but the cake carries more water.<\/p><\/div>\n

Gypsum sludge<\/h3>

Calcium sulphate is the one sludge here that several machines can take: a chamber press, a centrifuge or a vacuum belt. It releases water more readily than the hydroxide sludge, which is why the choice widens for this one.<\/p><\/div>\n <\/div>\n <\/div>\n

Which of the three a plant produces is decided by the effluent, not by the press. Two of them normally end up on a chamber filter press.<\/p>\n <\/div>\n<\/section>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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Selection<\/p>\n

Follow the duty, not the catalogue<\/h2>\n

Read down the first column. The machine follows from three things: how fine the solids are, whether the cake has to be washed, and how much water has to leave before the cake can be moved.<\/p>\n

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Duty<\/span>Machine<\/span>Why<\/span><\/div>\n
Acid leach residue<\/span>Membrane filter press<\/span>Fine solids holding pregnant liquor. The cycle needs a squeeze and a displacement wash.<\/span><\/div>\n
Bayer red mud<\/span>Membrane presses in parallel<\/span>Caustic, sub-ten-micron solids, very large tonnage. Built for a stackable cake.<\/span><\/div>\n
Precious metal slime<\/span>Small membrane press<\/span>Low tonnage, high value. Capture and wash matter more than speed.<\/span><\/div>\n
Concentrate<\/span>Chamber or membrane press<\/span>The solid is the product, so moisture is shipped weight.<\/span><\/div>\n
Sulphide sludge<\/span>Chamber filter press<\/span>Thin feed, small dry tonnage. The cake has to be handleable on site.<\/span><\/div>\n
Neutralisation sludge<\/span>Chamber filter press<\/span>Largest sludge volume. Lime process, firm cake without flocculant.<\/span><\/div>\n
Gypsum sludge<\/span>Chamber press, centrifuge or vacuum belt<\/span>Settles readily and releases water. More than one machine can take it.<\/span><\/div>\n
Plant effluent sludge<\/span>Belt filter press<\/span>Continuous, dilute, flocculated. Cake dryness is not the binding constraint.<\/span><\/div>\n <\/div>\n

Eight duties, five machine types, and one row that belongs to a belt press. The hydrometallurgy filter press takes the other seven, in different builds. That is why one site can run two kinds of press and be correctly equipped.<\/p>\n <\/div>\n<\/section>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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The presses<\/p>\n

Three press types carry the value line<\/h2>\n

All three are hydrometallurgy filter press builds running batch cycles. What separates them is whether the cycle includes a squeeze and a wash, how large the pack is, and how much of the discharge happens without an operator.<\/p>\n

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\"Fully<\/figure>\n
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Membrane filter press<\/h3>

Chambers fill, membranes squeeze, wash water displaces the liquor, air clears the core. On leach residue and refinery slime this is the step that recovers the metal. Membrane filter press →<\/a><\/p><\/div>\n

Recessed chamber filter press<\/h3>

For caustic tonnage rather than dissolved value: red mud and neutralisation sludge on a polypropylene pack, with wearing parts that sit flat and come out singly. Recessed chamber filter press →<\/a><\/p><\/div>\n

Automatic filter press<\/h3>

High-cycle circuits. Plate shifting and cake discharge run on a programme, so one operator covers the shift instead of standing at the pack. Automated filter press →<\/a><\/p><\/div>\n <\/div>\n <\/div>\n <\/div>\n<\/section>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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Where the belt fits<\/p>\n

One duty on this site belongs to a belt press<\/h2>\n

A belt filter press is continuous. It wants a dilute, flocculated feed and a steady flow, and it returns a cake that is wetter than a press cake. Those conditions do exist in a metallurgical plant. They just are not where the metal is, and where the metal is, the duty stays on a hydrometallurgy filter press.<\/p>\n

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What it takes<\/h3>\n