Scheelite dressing can use gravity, magnetic and flotation separation. The types and properties of the ore decide the separation methods and processes. Basing on good floatability of scheelite, the flotation is selected.
Scheelite flotation product line is suitable for the scheelite containing multi metals with complex structure.
Concentration pulp with high temperature is common method. First, the pulp is concentrated to 60%-70%; the next, sodium silicate is added into pulp; then, the pulp is heated to 80℃ and stirred for 30-60min; the last, it is diluted with water. The floatation of scheelite is under the room temperature, and the product in tank is calcspar & fluorite.
It is difficult to separate scheelite and barite by sodium silicate because of the closed inhibitory action for scheelite and barite. We choose alkyl sulfate as collector to repeatly select barite under the 1.5-3PH, and the product in tank is scheelite.
Xanthate is used to capture sulfide minerals in scheelite floatation. We add a little oxide and sodium sulfide to inhibit sulfide without floatation.
Oleic acid as collector and sodium silicate as inhibitors, which could inhibit the quartz and silicate gangue and float scheelite.
It interfered the scheelite floatation index for complex composition, fine particle size of distribution and containing fluorite and other mineral rich of Ca & Fe. The dressing plant takes the processing: one roughing, four cleaning and two scavenging, but the final grade of scheelite was not high only 55%. So they authorize Xinhai to do technical reconstruction. Xinhai decided to use centrifugal flotation process after analyzing the properties of ore, the detailed index comparison as follow:
|Comparison of Reformation||Process||Concentrate Grade/%||Recovery Rate/%|
|After Reformation||Centrifugal Flotation||62.59||93.26|
After the reconstruction, it obviously strengthens the recovery of fine particle and reduces the effect of mud on the separation process. The recovery index becomes better realizing the comprehensive recycling of resources.