The Flotation Research On Recovery Of Scheelite From A Tungsten Tailings

Mineral resources are a kind of non-renewable natural resources.With the progress of beneficiation technology and the depletion of mineral resources,tailings have become an important secondary resource for development and utilization.A certain tungsten tailings in Jiangxi Province has been stored for a long period of time.Recycling and reusing the tungsten tailings can achieve certain economic value,and can also alleviate the problems of environmental pollution and safety which are brought about by tailings dumping year by year.At present,the use of tungsten tailings is mainly divided into two aspects:recycling of valuable metals,overall utilization(tungsten tailings as raw materials,production of cement,glass,ceramic particles,mineral polymer materials.etc.).Tungsten is known as the"industrial tooth" and has an extremely important application in iron and steel metallurgy,energy and chemical industry,information technology and so on.This paper mainly studies how to recover tungsten from tailings by the method of mineral processing.The tungsten tailings were analyzed by X-ray fluorescence analysis,multi-element chemical analysis,phase analysis of tungsten elements,XRD diffraction pattern analysis,particle size analysis,etc.The results showed that tungsten is the main metal that deserves to be recovered,and the content of WO3 is 0.30%,that the tungsten in the tailings is mainly in the form of scheelite,and the main gangue minerals are quartz,fluorite,calcite,beryl,and potassium feldspar,and that the proportion of tungsten tailings whose paticle size is less than 0.074 mm accounts for 52%,and the metal distribution rate is about 58%.Through a series of beneficiation experiments,the appropriate conditions for the roughing stage of white tungsten are determined as follows:the fineness of less than-0.074 mm accounts for 78.59%,the dosage of lime and sodium carbonate was 1200 g·t-1 and 1000 g·t-1 respectively,CMC+Na2SiO3 acted as combined inhibitor whose dosage was 40 g·t-1+4000 g·t-I,the dosage of lead nitrate was 300 g·t-1,and the dosage of combined collector ZL+GY-2 was 300 g·t-1t+200 g·t-1,with the flowsheet of 'one roughing,two scavenging" the crude concentrate with WO3 grade was 2.03%and recovery rate was 65.76%can be obtained.The XRD diffraction pattern analysis showed that the main gangue minerals in the crude tungsten concentrate are fluorite and calcite.Therefore,adopting scheelite heating-cleaning method is better for ore adaptability,and the operating conditions for this stage are as follows:pulp concentration was R=50%,temperature was about 70?.,heating and stirring time is 1h,the amount of collector ZL,GY-2 was 15 g·t-1 and 10 g·t-1,respectively,and the amount of sodium silicate was 6000 g·-1.The process exploration experiments showed that with the increase of cleaning times,the grade of tungsten concentrates did not increase,however,the recovery rate decreased rapidly.Therefore,in this scheelite heating-cleaning stage,we used the flowsheet of "one roughing,one scavenging".According to what has been stated above,for a tungsten tailings with the grade of WO3 is 0.31%,when adopting "one roughing,two scavenging" in the scheelite roughing stage and "one roughing,two scavenging" in the scheelite heating-cleaning stage,the tungsten concentrate with WO3 grade and recovery is 8.29%and 52.32%respectively,can be achieved.The single mineral flotation experiment showed that the buoyancy of the three calcareous minerals(scheelite,fluorite and calcite)was relatively close when ZL was used as a collector.The relative order was calcite>scheelite>fluorite;When Na2SiO3+ CMC as inhibitors,the floatability of scheelite is almost unaffected,however,the buoyancy of fluorite and calcite is drastically reduced,indicating that sodium silicate and CMC can be used as a combination inhibitor to achieve the selective inhibition of fluorite and calcite;The chemical analysis of sodium silicate solution showed that Si(OH)4 and SiO(OH)3-are the main components that can inhibit the gangue minerals;The infrared spectrum test results showed that the adsorption of CMC on the surface of scheelite is very weak,however,chemical adsorption occurs on the surface of fluorite and calcite,indicating that CMC has weak effect on scheelite surface and relatively strong selective inhibition effect on fluorite and calcite surface.