| The main components of yellow phosphorus slag are silica and calcium oxide,which are important secondary resources for the production of silicon and calcium related products.In this experiment,the yellow phosphorus slag with high content of silica was used to extract calcium ions from yellow phosphorus slag in the nitric acid of low concentration.The inorganic polymer polysilicate flocculant with good flocculation effect was prepared by polymerization and activation of silica rich filter residue,and it was applied to the treatment of phosphate ore reverse flotation wastewater,which can not only make use of industrial waste yellow phosphorus slag,consume industrial pollutants,but also reduce the production cost of polysilicic acid flocculant.It can be used to treat phosphate ore reverse flotation wastewater to treat waste,and also provides a new way of thinking for the three wastes treatment of phosphorus chemical industry.Therefore,this experiment has important theoretical significance and application value.Firstly,the physical properties of yellow phosphorus slag were characterized.The results show that the main phase of yellow phosphorus slag is composed of Si-O and Ca-O bonds,and the content of silica and calcium oxide is 40.56% and 46.40% respectively.The average particle size of the particles is 13.31 um and the size is small,which is suitable for the subsequent leaching process.The low concentration of calcium nitrate leaching yellow phosphorus slag,calcium ion leaching optimum conditions: nitrate concentration was 14%,nitric acid and phosphorus slag liquid solid mass ratio is 9:1,the leaching reaction at normal temperature(20 ?),stirring speed is 400r/min,the leaching reaction time is 20 min.Under the optimum conditions,the leaching rate of Ca O in yellow phosphorus slag reached 99.03%.Secondly,three different methods were used to deal with the polysilicic acid intermediates prepared by nitric acid decompositi on of yellow phosphor furnace slag.Research shows that have shown that the polymeric silicic acid flocculant prepared from nitric acid decomposition of yellow phosphor furnace slag has good flocculation performance,and the filtration and washing process will The polysilicic acid flocculant was essentially inactivated,and its re-adjustment with nitric acid again caused the inactive polysilicic acid to regain its activity,but the flocculation performance after recovery was lower than that of the unfiltere d and washed flocculant.Then the influencing factors affecting the treatment effect of polysilicic acid flocculant on phosphate flotation reverse flotation wastewater were studied,and the most suitable process conditions for wastewater treatment were det ermined: the dilution ratio of phosphate rock reverse flotation wastewater was 10,and the p H was 9.1.The activation temperature was 25?,the activation time was 50 min,the flocculant addition amount was 5m L/L,the flocculation temperature was 55?,and the flocculation settling time was 10 min.Under the optimum conditions,the removal rate of turbidity of phosphate flotation reverse flotation wastewater was 99.12%,and COD removal rate was 97.69%.Finally,the hydraulic conditions of the flocculation e xperiment was explored via the orthogonal experiment,and the sedimentation dynamics of the flocs were discussed under the optimal hydraulic conditions.Orthogonal test results show that the experiment of polysilicic acid flocculant in the treatment of rev erse flotation of phosphate rock is better in the square beaker,and the optimal turbidity is 3 after sinking.The flocculation settling kinetics was simulated using the second-order kinetics model and the hyperbolic model respectively.The fitting results show that the hyperbolic model can better express the flocculation process of the flocculation of phosphate flotation reverse flotation wastewater by using polymeric silicic acid flocculant. |
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