Experimental Research On Beneficiation Of Iron-tin Ore In Kachin State

Tin metal is widely used in many fields of economy and national defense construction for its advantages.With the rapid growth of demand for tin resources in economic development and the exhaustion of easy-to-select tin resources,iron-tin ore,a kind of refractory tin resource,has attracted the attention of researchers at home and abroad.The purpose of this paper is to develop a new and efficient separation circuit for iron-tin ore in Kachin State,Myanmar,and to provide reference for the separation of iron-tin ores with similar properties in China.The value of practical applications is huge.The raw ore contains 0.495% tin and 29.79% iron,the main metal minerals in the ore are magnetite,cassiterite,hematite,limonite,pyrite and a small amount of siderite and chalcopyrite,the gangue minerals are mainly quartz,muscovite,calcite,kaolinite,calcium iron garnet and a small amount of dolomite,chlorite,fluorite and apatite,the content of harmful elements such as arsenic and phosphorus is low.Tin mainly occurs in cassiterite(90.56%)and cassiterite is mostly enclosed in quartz,which is self-shaped granular and columnar;iron mainly occurs in magnetite(43.99%),hematite(35.92%),limonite(14.56%)and pyrite(2.80%),magnetite and hematite are mostly metasomatized and altered in the form of automorphic granular and plate.Fine pyrite is often wrapped in some magnetites.The iron concentrate of high grade,containing 0.06% sulphur,with a yield of 20.91%,iron grade of 65.20% and recovery of 45.76% can be obtained by using technological processes to treat the raw ore,which consist of low intensity magnetic roughing of raw ore under the grinding fineness-0.074 mm accounting for 50%,regrinding and re-separation of crude concentrate under the grinding fineness-0.074 mm accounting for 55%,which is from low intensity magnetic roughing and desulfurization of iron concentrate by flotation,which is from re-grinding and re-separation.Tin crude concentrate with yield of 4.01%,tin grade of 7.893% and recovery of 63.94% and tin midding of one stage shaking table with yield of 20.08%,tin grade of 0.407% and recovery of 16.51% can be obtained from the tailings of low intensity magnetic roughing by gravity separation of one stage shaking table.Tin crude concentrate with yield of 0.29%,tin grade of 10.719% and recovery of 6.28% can be obtained from tin midding of one stage shaking table,the grinding fineness-0.074 mm accounting for 80%,by multiple processes including pulsating high gradient magnetic separation and gravity separation of two stage shaking table.The comprehensive yield,grade and recovery of crude tin concentrate in the first and second stage shaking table are 4.30%,8.084% and 70.22%,respectively.Tin concentrate with yield of 0.57%,tin grade of 58.743% and recovery of 67.16% can be obtained from tin combined crude concentrate by multiple processes including flotation desulfurization and weak magnetic-high gradient magnetic separation for iron removal.The full-flow test shows that treating raw ore by low intensity magnetic roughing,regrinding and weak magnetic concentration of weak magnetite coarse concentrate,desulfurization of iron concentrate by flotation;first stage shaking table gravity separation of weak magnetic roughing tailings,high gradient magnetic separation of tin midding of one stage shaking table after regrinding,gravity separation of magnetic separation tailings,flotation desulfurization,weak magnetic-high gradient magnetic separation,we can get high grade iron concentrate,containing 0.06% Sulphur,with yield of 21.62%,iron grade of 65.19% and recovery of 47.31%;tin concentrate with yield of 0.58%,tin grade of 58.039% and recovery of 68.01%;pyrite concentrate with yield of 0.76%,pyrite grade of 47.49% and recovery of 36.83%;sub iron concentrate?with yield of 2.30%,iron grade of 61.86% and recovery of 4.78%;sub iron concentrate?with yield of 15.54%,iron grade of 40.90% and recovery of 21.34%.