Study On Gravity-flotation Combination Beneficiation Process Of Mid-low Grade Collophane

Phosphate ore is a valuable strategic resource in our country.Its cumulative reserves is abundant,but most of it is mid-low grade collophane that is difficult to be upgraded.As the rapid consumption of rich phosphate ore resources,to realize efficient utilization of phosphate ore resources,the research of separation technology for mid-low grade collophane is of great importance.The mid-low grade collophane from Yichang,Hubei Province is research object in the tests.According to character of the raw ore,on the basis of the direct reverse flotation exploratory tests,the gravity-flotation combination beneficiation process was determined to separate the phosphate ore.The related conditions and separate effect of combination process have been investigated.In addition,the improvement of flotation stage in gravity-flotation combination beneficiation process by sodium dodecyl sulfate?SDS?was conducted,and the related action mechanism of SDS was explored.Finally,the character of final concentrate product from closed-circuit test has been analyzed.The main content and results in this research showed as follows:The phosphate ore main contains quartz,feldspar,dolomite,calcite and clay gangue minerals.It is characterized by complicated types of impurities,close association between objective mineral and gangue minerals,and small disseminated grain-size.The direct reverse flotation exploratory test was performed to separate the ore,and the results showed good separate effect but problem of large reagents consumption and high processing cost.Based on this,the research of gravity-flotation combination beneficiation tests were conducted to separate the phosphate ore.The results of combination process showed that:under the optional process conditions,the concentrate with P₂O₅ grade 31.29%?MgO grade 0.93%?P₂O₅ recovery 89.10%is attained.Compared with direct reverse flotation process,spiral chute?h/D=0.36?is adopted in gravity separation stage of this process to concentrate feed with P₂O₅ grade23.78%,and the gravity concentrate with yield 47.43%?P₂O₅ grade 28.95%is attained,which reducing the load in direct flotation.Based on this,when separating 1 t raw ore,the combination process can save sodium carbonate by 1.6 kg,sodium silicate by 0.3 kg,collector?ZY-1?by 0.3 kg and phosphoric acid by 1.9 kg,showing obvious economic benefits and environmental benefits.In addition,for the problem of high acid consumption and processing cost in reverse stage of combination process,Sodium dodecyl sulfate?SDS?was used as a dolomite collector to reduce the acid consumption from 6.1 kg/t to 3.9 kg/t when no other reagents were present.At the same time,the similar separate effect was attained and the final phosphorus concentrate from closed-circuit test meets the requirements of fertilizer production.By means of Zeta potential analysis,single mineral flotation tests,infrared spectrum detection,and theoretical analysis,the results indicates that the acting force between SDS and collophane or dolomite is weak,and that the favorable separation effect between collophane and dolomite can be attributed to the electrical repulsion difference between mineral surface and collector.According to the research,an economical and effective gravity-flotation combination beneficiation process for mid-low grade collophane has been come up with,and related mechanism was analyzed.The research aims at providing the reference for separating the ore.