4 Q&A You need to Know about Mineral Washing Process

Mineral washing refers to the process of scrubbing the ore cemented by clay or containing a lot of mud by hydraulic or mechanical force, so that the ore is broken up, and the fine mud on the surface of the ore is washed and separated. Mineral washing process is often used to process clay iron ore, manganese ore, apatite ore and placer of gold, platinum, tin and tungsten.

This article will take you to further understand the mineral washing process from four aspects: the purpose, process, types and choice of common equipment of mineral washing.

Due to the long-term weathering of alluvial, sedimentary placer or oxidized mineral deposits in nature , a large number of fine clays are formed on the surface of some gangue minerals, which will seriously affect the operation of separation process. Therefore, it is very important to set up the mineral washing operation. Generally, there are three main purposes of ore washing operations: prevent blockage, obtain concentrate and improve product quality.

(1) Prevent blockage. When processing ore with much mud and water, it is easy to block ore bins, chutes, hoppers and crushing and screening equipment, which will reduce the processing capacity of crushing and screening equipment. When the blockage is serious, the production cannot be carried out normally. At this time, ore washing process is often considered to reduce blockage.

(2) Obtain concentrate. Some ores can be washed to enrich useful minerals and obtain qualified concentrates,such us some sedimentary manganese ore, apatite ore, iron oxide ore and so on.

(3) Improve product quality. The smelting limestone can be washed to remove the sludge and improve the quality to meet the smelting requirements.

Mineral washing process includes two operations: the crushing of clay and the separation of the dispersed clay from granular and massive materials.

The crushing operation is the process in which the clay is dispersed by washing and soaking with water, or by mechanical agitation and grinding. If necessary, dispersants (such as sodium silicate) can be added to promote dispersion.

The separation operation is mainly to separate the clay from the ore particles according to the different particle size. Generally, the sludge is separated by wet screening or hydraulic classification. Therefore, mineral washing is actually the gravity separation process according to particle size.

Common mineral washing equipment mainly includes hydraulic washing screen, cylinder washing machine, cylinder scrubbing machine and spiral washing machine. In addition, various screening equipment (such as fixed bar screen, roller screen, vibrating screen, etc.) can also be used in the ore washing stage.

(1) Hydraulic washing screen. This is a washing method to wash on fixed sieve using water gun, and is often used for easy-to-wash ore.

(2) Cylinder washing machine. Cylinder washing machine includes trommel screen and cylinder scrubbing machine. Cylinder sieve speed is high, the inner wall of the sieve cylinder is equipped with longitudinal lift plate annular baffle and high pressure water spray device, in order to improve the crushing ability, often used for easy-to-wash ore.

(3) Cylinder scrubbing machine. The cylinder of the cylinder scrubber is divided into two sections. The front section is non-porous, used for soaking and crushing ore, and the rear section has holes for the separation of debris.

(4) Spiral washing machine. Spiral washing machine is often used for hard-to-wash ores, and has a strong scrubbing effect. The ore washing efficiency can be improved by soaking the ore in advance, setting high pressure water spraying, applying vibration and adding a small amount of agents (such as 1% concentration of NaOH) in the ore washing process. The ore washing efficiency has a great influence on the ore dressing.

(5) Screening equipment. In some mineral processing plants, the screening equipment in the crushing and screening stage can also be used as washing equipment at the same time. This process does not require special mineral washing equipment, has low investment and is convenient to operate. And it is suitable for processing easy-washing ore with low mud content and low soil plasticity.

The choice of ore washing equipment and its processing capacity mainly depend on the washability of the ore. The washability of ore can be evaluated according to indicators such as clay plasticity index, washing time, power consumption and washing efficiency. The relationship between the washability of ore and the selection of mineral washing equipment can be seen in table 1.

Table 1 The Choice of Mineral Washing Equipment for Different Ores

The above introduce the mineral washing purpose, process, types and choice of common equipment. Mineral washing process can effectively remove the clay impurities attached to the surface of the ore, which is conducive to the normal operation of the ore dressing operation. If you want to know more ore washing information, or want to buy ore washing equipment, you can consult the online customer service or leave a message, we will contact you soon.