Application Of Compound Collector In Reverse Flotation Of High Phosphorus Oolitic Hematite And Treatment Of Wastewater

Our country is rich in iron ore resources,97% of which are low grade ore that can not collected by normal way.Large number of low grade ore such as high phosphorus oolitic hematite has not been used.In recent years,compound with anionic collectors made a major breakthrough in the reverse flotation technology.But iron ore should be fine grinding before reverse flotation,a variety of agentia join in the processe,which lead to complex wastewater components,properties instable and great harm.With environmental protection is strongly advocated,the development of high efficiency,low toxicity and safety of low grade iron ore flotation reagents and waste water recycling has become a trend.Enshi oolitic hematite,mainly including oolitic structure and disseminated structure,used as the main raw material.The gangue minerals are mainly quartz,oolite chlorite etc.The paper study a fatty acid compound collector(915 BM)reagent regime and process flow in the reverse flotation of the ore application process.Finally adopted "one stage roughing two stage scavenging and one cleaning" closed-circuit processes.The pulp temperature about 25 ℃,pH of 11.2,NaOH dosage of 1000 g/t,soluble starch dosage of500 g/t,calcium oxide dosage of 500 g/t,collector 915 BM dosage of 600 g/t in roughing.Select 915 BM collector dosage of 150 g/t,scavenging soluble starch dosage dosage of 200g/t.Obtain the iron concentrate grade of 56.10%,the comprehensive recovery iron of67.39%,phosphorus content is 0.23%.After reverse flotation circuit,the waste water indexes of turbidity 95780 NTU,suspended solids 1272 mg/l,pH 9.6.Through natural subsidence is difficult to reduce turbidity.After analyzing the water quality,choose coagulation precipitation process.Choosing the method of mixing with lime,polyacrylamide,by comparing several treatment effect of different coagulants.And the dosage of 350 mg/l and 20 mg/l,stirringspeed of 80 r/min,Turbidity index turbidity reached to19.9 NTU,which leading the effluent rate can reach 80% to 90%,after coagulation sedimentation.Compared the different proportion(after wastewater treatment volume/water volume)filling water in roughing reverse flotation process from product indicators,all of concentrate iron grade is around 54%.After processing waste water can almost all be recycled.The mechanism of collector and coagulant was analyzed by means of infrared spectrum analysis,surface tension,zeta potential and scanning electron microscopy.The results show that the collector can collect the concentrate from raw ore by absorbing in the surface of ore and changing the surface electrical and reverse flotation solution surface tension.Coagulant could reduce turbidity and suspended material of waste water by through “electrostatic bridge” role,double shell adsorption and bridge working together.Most of wastewater can be recycled,so it can reduce resource waste and environmental pollution brought by the direct emissions.