Wolframite and Scheelite Mixed Tungsten Ore Flotation (1)
Wolframite and scheelite are different with the same name, there are all “w” but their body structure are not the same, so their beneficiation method is different, black tungsten gravity commonly used the separation method, scheelite commonly used flotation process.
After years of development, our country each has a solid industrial foundation of beneficiation technology in wolframite and scheelite tungsten ore flotation. From a single scheelite recovery of scheelite in bed or recovery of wolframite from single black tungsten deposit is relatively easy. But why there is a certain type of skarn deposits made mistake like, they try to make the black and white tungsten together under the same roof, so the deposit is called "black and white mixed tungsten deposit.
Mixed black and white tungsten ore flotation is a worldwide difficult problem, in this type of ore deposits, the black and white tungsten are in fine grained disseminated separately symbiosis in the strata, although there are all tungsten, they have always not buying it from one another, they go their own way. The difficulty of black and white mixed tungsten ore mixed is that the inclusion of black tungsten, In Jiangxi quartzite mines, black tungsten can be solved with gravity separation, magnetic separation, but when it comes to in the skarn deposits, it also learn pee-a-boo from scheelite, escapes from the gravity separation method. Of course the most embarrassing thing is that the suspect relationship, in the process of flotation of wolframite and scheelite natural flotability difference is bigger, often the flotability of scheelite is superior to the black tungsten, tungsten oxide ore collector line of collecting ability is stronger, collecting of wolframite ability is weaker; In addition, wolframite and scheelite the best flotation pH interval does not agree, the best flotation pH interval of scheelite is relatively narrow, between 7-9.
Wolframite the best flotation pH interval often swings between 5-10. And wolframite it brittle than flotation technology, only after a minor in the coarse grinding, into the coarse grain of spiral classifier wolframite precipitation will be priority major, with the sand return to the mill grinding again, until the grain will overflow into the sorting operation. It caused most of the classification system of wolframite granularity are belong to fine grain or even micro-fine particle, general flotation reagents are difficult to catch.
In the past, wolframite and scheelite separation method of mixed flotation concentrate with room temperature and heating method of two kinds: normal temperature method is in a large amount of sodium silicate for rough concentrate (60 ~ 90 k young) under normal temperature stirring, to curb the fluorite and calcite, quartz and other gangue minerals, and most of wolframite is restrained, white tungsten concentrate were obtained through the multiple selection, room temperature method is more difficult to obtain high grade tungsten concentrate containing WO365 % above, and the dosage of sodium silicate is more large consumption. Heating method only need to add a relatively small amounts of sodium silicate, and then heated to 90 ℃ or so, thermal agitation for an hour, this process makes the gangue minerals and wolframite surface adsorption of collector stripping, and strong inhibition by sodium silicate, and scheelite collector can still on the surface of the solid adsorption, thus containing WO365 % above the high grade can be obtained by flotation of scheelite concentrate, cleaner tailings need to recycle of black tungsten, the traditional process is: the black tungsten content is less, usually with magnetic separation enrichment,and shaking table selection for black tungsten concentrate, the black tungsten content is higher, can be directly with the table selected black tungsten concentration, The process of the disadvantage is the microgranular wolframite erosion, recycle like go through the motions, is better than nothing, only so many of the early black and white tungsten mixed mining waste is serious, the efficiency is low. There would have a more effective way to realize whether black and white tungsten mixed flotation?