An alluvial tin processing plant is a facility that extracts and purifies tin from alluvial tin ore. The following is an introduction to it:
Process Flow
Washing and Screening: The alluvial tin ore usually contains a lot of impurities such as clay, sand, and gravel. First, it is washed by a washing machine to remove the mud. Then, it is screened by a trommel screen to separate large stones and other waste materials. For example, in the Congo (Kinshasa), the alluvial tin ore is fed into a drum washing and screening machine. Under the scouring of strong water flow and the rotation of the drum, the clay is peeled off and dispersed, and the coarse gravel is screened out.
Scrubber Trommel
Rough Concentration: After washing and screening, the qualified pulp enters the jig concentrator for rough concentration. The jig concentrator uses the pulsating water flow to make the tin ore particles settle to the bottom due to their large specific gravity to form concentrate, while the light minerals are discharged from the upper part and the tail. In the alluvial tin ore processing in the Congo (Kinshasa), the 2-8mm coarse sand - sized material enters the saw - tooth wave jig concentrator for separation, and the recovery effect of medium - and coarse - grained cassiterite is good.
Jig Machine
Classification and Cleaning: The rough concentrate produced by the jig concentrator enters the shaking table for cleaning. According to the feed particle size, different types of shaking tables are selected. The shaking table makes the mineral particles move along different paths through the reciprocating asymmetric motion of the table surface and the washing of the transverse water flow, and finally high - grade tin concentrate is obtained. For extremely fine - grained materials, centrifugal separation equipment such as spiral chutes or centrifugal concentrators can be used as supplements.
Spiral Concentrator
Shaking table
Concentration and Dewatering: After enrichment, the tin concentrate needs to be concentrated and dewatered to increase the solid content and facilitate storage and transportation. Common equipment includes thickeners and filter presses.
Main Equipment
Washing Equipment: Such as sand washers, which can break up the mud mass, reduce the situation of tin mineral particles being wrapped in mud, and improve the tin recovery rate.
Screening Equipment: Trommel screens are usually used to screen out large - sized waste stones and divide the ore into different particle sizes for subsequent processing.
Beneficiation Equipment: Including gravity separation equipment such as jig concentrators and shaking tables, as well as magnetic separation equipment and electric separation equipment for tin ores containing magnetic minerals or minerals with different electrical properties.
Dewatering Equipment: Such as dewatering screens, thickeners, and filter presses, which are used to remove excess water in the ore concentrate to obtain tin concentrate products that meet the requirements.
Plant Design Considerations
Ore Properties: The design of the alluvial tin processing plant needs to be carried out according to the specific properties of the alluvial tin, such as the particle size of the tin ore, the content of associated minerals, and the degree of monomer dissociation. For example, if the tin ore has a low monomer dissociation degree, a rod mill needs to be used to liberate the tin minerals; if it contains magnetic minerals, a magnetic separator needs to be configured.
Water Resources: Since the washing and beneficiation processes of alluvial tin ore require a large amount of water, the plant should be located near a water source or a large - scale water storage tank should be built, and a complete water recycling system should be equipped to improve the utilization rate of water resources and reduce environmental pollution.
Environmental Protection Requirements: The tailings and wastewater generated during the processing of alluvial tin ore contain certain harmful substances and need to be properly treated. The tailings need to be transported to the tailings pond for safe storage, and the wastewater needs to be treated to meet the discharge standards to avoid polluting the environment.
