Abstract: The contents of P2O5, SiO2 and CaO in a phosphate mine in Yunnan are 18.59%, 37.37%, and 27.55%, respectively. It can be seen that this ore belongs to silica-calcareous collophanite. According to the properties and characteristics of this ore, the flotation test was carried out by using the direct-reverse flotation flow. Firstly, the optimal dosage of each reagent was determined by a single factor condition test. On this basis, the response surface methodology was used to further optimize the dosage of three kinds of regulators in positive flotation. Finally, based on the results of the single factor condition test and response surface methodology optimization, closed-circuit flotation test was carried out. The results of the single factor condition test showed that the optimal dosage of Na2CO3, Na2SiO3, YP6-1 in direct flotation, YP6-1 in reverse flotation, modified starch DZ, H2SO4 and H3PO4 were determined to be 3000, 1500, 2400, 600, 700, 5000, and 4000 g/t, respectively. Under the optimum dosage of these reagents, phosphorus concentrate with P2O5 grade and recovery of 30.19% and 73.06% can be obtained by a direct-reverse flotation. The response surface optimization experiment revealed that the optimal dosages of Na2CO3, Na2SiO3, and modified starch DZ in direct flotation were 3016.15, 1986.72, and 877.33 g/t, respectively. Actual flotation tests conducted under these conditions resulted in a concentrate with a P2O5 grade of 30.08% and a recovery of 75.81%, which was found to be in good agreement with the predicted results. Compared with the results of the traditional single factor condition test, the recovery can be increased by 2.75 percentage points while maintaining the same grade by using the response surface methodology. Finally, the closed-circuit flotation test was carried out based on the result of the single factor condition test and response surface optimization. The phosphorus concentrate with P2O5 grade of 32.07% and recovery of 72.83% was obtained, which indicates that a good flotation effect of the refractory fine collophanite has achieved.

Key words: Collophanite, direct-reverse flotation, single factor test, response surface methodology, interaction

摘要： 云南某磷矿P2O5, SiO2和CaO含量分别为18.59%, 37.37%, 27.55%，属于硅钙质胶磷矿。根据该矿性质特点，采用正-反浮选流程，在单因素条件试验的基础上，通过响应曲面法对正浮选中调整剂用量进行优化，并基于优化结果开展闭路浮选试验。单因素试验结果表明，Na2CO3、Na2SiO3、正浮选YP6-1、反浮选YP6-1、改性淀粉DZ、H2SO4和H3PO4的最佳用量分别为3000, 1500, 2400, 600, 700, 5000和4000 g/t，在此药剂用量下经一正一反浮选可获得P2O5品位和回收率分别为30.19%和73.06%的精矿产品。响应曲面优化试验结果表明，正浮选中Na2CO3、Na2SiO3、改性淀粉DZ最佳用量分别为3016.15, 1986.72和877.33 g/t，在该条件下进行实际浮选试验得到P2O5品位和回收率分别为30.08%和75.81%的精矿，该结果与响应曲面优化拟合结果基本一致。与传统的单因素条件试验结果相比，采用响应曲面法优化可在品位相当情况下将精矿的P2O5回收率提高2.75个百分点。最后，根据单因素条件试验和响应曲面优化确定的条件进行闭路浮选试验，获得了P2O5品位32.07%、回收率72.83%的磷精矿，较好地实现了该难选细粒胶磷矿的分离回收。

关键词: 胶磷矿, 正—反浮选, 单因素试验, 响应曲面法, 交互作用