Tin ore is one of the important strategic mineral resources, and tin and tin alloys have been widely used in modern national defense, industry, cutting-edge science and technology and human life.
At present, the common ones mainly include gravity separation method, flotation method and magnetic separation method, that is, the raw ore is washed and deslimed, crushed and screened, pre-selected, and then passed through one of the gravity separation equipment, flotation equipment and magnetic separation equipment. One or more kinds of beneficiation equipment are used for processing, and finally a tin concentrate with ideal grade and recovery rate is obtained.
1. Gravity separation process of tin ore
At present, the vast majority of tin concentrates come from cassiterite deposits, and the density of cassiterite is higher than that of co-existing minerals. Therefore, gravity separation has become one of the main beneficiation processes for tin ore, and is often used to separate tin sand ores.
The gravity separation of cassiterite is generally the separation of ore sand. Generally, a multi-stage grinding and multi-stage separation process is adopted, which can realize the principle of early dissociation, early recovery and early tailing, and avoid excessive crushing caused by unevenly embedded cassiterite.
Since cassiterite will produce slime in the crushing and grinding stage, grading desliming is an important preparatory operation before cassiterite re-election. It can also control the selected particle size while removing the interference of ore slime. Generally, ore washing machines, cross-flow belt chutes, small Calibre cyclone and other equipment are used as cassiterite desliming equipment. The commonly used tin mines are mainly jigs and shakers.
2. Tin ore flotation process and equipment
Due to the low separation efficiency of cassiterite gravity separation for tin minerals with a particle size below 19 μm, flotation has become one of the important ways to recover fine-grained tin minerals. And other issues.
At present, there are two methods to improve the effect of fine-grained cassiterite flotation: one is to pretreat fine-grained tin minerals before flotation; the other is to use effective flotation reagents and equipment combinations.
Common pretreatment methods include intensive slurry stirring, large-diameter hydrocyclone classification, small-diameter desliming, lowering the lower limit of classification particle size and the lower limit of desliming particle size.
3. Tin ore magnetic separation process and equipment
Since some tin ores often contain various iron oxide minerals (such as magnetite, hematite and limonite, etc.), tungsten ore and other symbiotic minerals, these minerals cannot be very good with cassiterite by flotation and gravity separation. separated.
Therefore, magnetic separation is often used in the washing process to realize the separation of tin and iron. The magnetic separation of tin ore is mainly wet strong magnetic separation, which is used for the raw ore, secondary concentrate and concentrate before entering the gravity separation operation, while the dry magnetic separation process is often used to separate tungsten and tin minerals. Commonly used include wet magnetic separator and dry magnetic separator.
© 2021 Yantai KZ Mining Processing Technology & Equipment Inc.