Optimization of Scheelite Flotation Process

CaWO4 is generally affirmative scheelite crystal, a plate or crystal, there are dense, brittle, hardness is 5 ~ 5.5, density of 5.8 ~ 6.2g / cm3, no magnetism. Most of the scheelite deposit in China is a skarn type, with a fine granularity, often associated with or symbiotic with a variety of nonferrous metals such as molybdenum and bismuth, at the same time, there are calcium-bearing gangue similar to the flotation of tungsten ore, so flotation is an effective method to recover fine and even fine-grained scheelite.

optimization of scheelite flotation process image

The most typical process of scheelite flotation is the use of sodium carbonate (or sodium hydroxide) and sodium silicate as a regulator, fatty acid as a collector flotation scheelite, the commonly used method is sodium silicate - oleic acid sodium method, sodium silicate-metal salt-sodium oleate method, sodium carbonate-sodium silicate-sodium oleate method, sodium silicate-sodium hydroxide-sodium oleate method and lime method. These methods are characterized by the inhibition of fluorite and calcite and flotation of scheelite at high alkalinity and the difficulty in separating calcium-bearing gangue minerals due to their poor selectivity to sodium oleate. Therefore, the separation of calcium-bearing gangue minerals is generally the first to obtain low-grade crude ore containing tungsten.

Skarn scheelite has another characteristic is the more serious mud phenomenon, many of the scheelite embedded part of the rock is easy to dissociate, easy to mud when grinding, easy to float in the flotation process with the overflow of water excretion, affecting the total recovery rate. Therefore, improving the grinding process can effectively solve the problem of scheelite mud and improve the recovery rate.

After the 200-250 um vibrating screen is passed through the coarsely ground ore ore that is not deslimed, the oversize material is returned to rough grinding, and the ore material below the sieve is subjected to strong magnetic tailing to mainly throw away the magnetic garnet and other magnetic minerals, non-magnetic minerals after grinding into white tungsten room temperature flotation, rougher obtained concentrate and then a white tungsten heating selection, to obtain scheelite concentrate; Micropowder magnetite concentrate also implemented a room temperature flotation, this flotation of medium-sized ore into non-magnetic scheelite for fine grinding;

After the conventional scheelite flotation process optimization, scheelite flotation process more energy-efficient than ever before, more environmentally friendly, and the total recovery rate was improved, is a useful complement to scheelite beneficiation process.