Leaching tank Permeation tank

Small leaching tanks, or percolation vessels, can be made of metal and lined with various corrosion-resistant materials depending on the nature of the leaching medium. Large seepage ponds are typically constructed using reinforced concrete, with their inner walls lined with corrosion-resistant materials such as lead sheeting, fiberglass-reinforced plastic, diabase slabs, or tiles. The porous false bottom of the seepage pond is covered with palm netting, bamboo mats, or filter cloth. During the leaching process, several tanks are usually arranged in series to enable a countercurrent leaching system: fresh solid material is added to the last tank in the sequence, while the dilute solution is introduced into the first tank, and then sequentially pumped from one tank to the next. The more tanks there are, the higher the leaching efficiency—but the longer the process takes. Leaching tank It can also be arranged according to height, allowing the liquid to flow by gravity and eliminating the need for pumps. The commonly used leaching tanks have a mineral capacity of 12,000 tons.

Percolation tanks are particularly well-suited for processing porous and sandy materials but are not ideal for handling compacted, impermeable masses. The key factor ensuring good fluid flow through the material is the uniformity of particle size, rather than the actual size of the particles themselves. When solid particles vary significantly in size, smaller particles tend to fill the voids between larger ones, thereby slowing down the flow of the solution through the bed or even causing channeling, which can reduce leaching efficiency. Percolation tanks have a simple structure; when used in leaching processes, they consume little solvent and require minimal power. They can eliminate the need for expensive concentrators or filters. However, they occupy a large footprint and have long leaching cycles.

Leaching tank - Compressed air mixing tank

A cylindrical leaching reactor that uses compressed air as the power source to agitate solid materials. The Pachuca tank is a typical example of a compressed-air-agitated tank. Inside the tank, there is a central vertical pipe open at both ends, through which compressed air is introduced via another pipe. When the tank is filled with slurry, the compressed air flows into the tank through the conduit, causing the material to rise from the central pipe and descend through the annular space around it, thereby keeping the solid particles suspended. This type of tank is suitable for leaching finely ground solid materials and can be constructed from wood or steel plates. A commonly used design features a cylindrical tank with a 60-degree conical bottom, measuring 3 to 6 meters in diameter and 13 to 15 meters in height. The inner lining is made of appropriate corrosion-resistant materials such as rubber, fiberglass reinforced plastic, acid-resistant tiles, or diabase slabs. The operating air pressure ranges from 0.142 to 0.214 MPa. This tank boasts a simple structure, easy corrosion protection, no mechanical transmission components, and convenient maintenance. Such leaching tanks are employed at the Zhuzhou Smelter in China for the leaching of zinc calcine produced by the wet-process zinc smelting. The slurry is discharged using compressed air, and the tank has a volume of 100 cubic meters.