| After analyzing the common methods of removal of H2S,utilizing phosphate ore slurry to removal of H2S was proposed in this paper.The phase analysis of phosphate ore was carried out by X-ray diffraction?XRD?and some chemical analysis methods,for example,inductively coupled plasma?ICP?,were used for the analysis of phosphate rock composition.In addition,the performance,mechanism,calcium leaching and dynamic process of using phosphate were studied through the experiment.In the experiment of phosphate ore slurry removal of H2S,phosphate ore before and after calcination removal of H2S were studied.It was found that the H2S removal efficiency of phosphate ore slurry after calcination was 15 times higher than that of uncalcined phosphate ore slurry,and the removal efficiency of H2S above 90%phosphate ore slurry before and after calcination was 10 min and 150 min,respectively.Capacity of phosphate ore slurry removal of H2S was 81 times higher than that of deionized water by experiment.Deionized water removal of H2S relative to phosphate ore slurry can be ignored.The orthogonal experiment results showed that the parameters influencing the removal efficiency of H2S from high to low are the gasflowrate,phosphateoreslurryconcentration?solidcontent?,H2S concentration,temperature,oxygen content and agitation rate.Effect of the parameters affecting the removal efficiency of H2S,eg solid content,oxygen content,temperature,gas flow rate,H2S concentration and agitation rate were studied.The gas flow rate had great effect on removal of H2S.As the flow rate of gas mixture increases,the removal efficiency of H2S decrease,because the liquid retention time decreases,resulting in the gas escape before H2S and liquid not reacted completely.As the solid content increases,the gas-solid contact opportunity increases and the slurry pH value increases,resulting in an increase in H2S removal efficiency.In the process of the reaction,the consumption of hydroxide ion increases,the slurry pH value decreases and then the remove efficiency decreases,when the import H2S concentration increased.As the temperature increases,the removal of H2S increases.Reaction temperature increased from 25?to 65?,the removal efficiency after 135min began to decline.As oxygen content increased from 0.0%to 9.5%,the removal efficiency increased by 33.3%.The removal efficiency of H2S above 90%was 135min under the condition of oxygen content was 0.0%.The agitation rate had low effect on removal of H2S,and the optimal stirring speed is 1000 r/min.The mechanism of phosphate ore slurry removal of H2S had been analyzed by means of experiments,XRD and Inductive coupling?ICP?,which was mainly the role of neutralization reaction and other metal oxides?eg.iron oxide,magnesia?.In the process of phosphate ore slurry removal of H2S calcium oxide and trivalent iron accounted for 70.09%and 7.65%,respectively.In the experiment of phosphate ore slurry,calcium of calcium oxide leaching were studied,because phosphate ore slurry removal of H2S was mainly the role of calcium oxide and fluorapatite response will not be involved.As reaction temperature increase,diffusion coefficient increases,activation energy decrease and solubility of H2S decrease resulting in an calcium leaching increase.This was because that the diffusion coefficient increased and activation energy reduced was beneficial for the leaching of magnesium was greater than H2S solubility decrease adverse effect.When the H2S concentration increased,the leaching rate of calcium speeded up.And when the solid content increased,the leaching rate of calcium speeded up.This was because that the higher solid content resulting in the gas-solid contact opportunity increases was beneficial for the leaching of calcium.When the stirring speed increases,the leaching rate of calcium increased.The optimal stirring speed was 1000 r/min.As the gas flow rate increases,the leaching rate of calcium increased.The optimal gas flow rate was 300ml/min.The leaching rate of calcium under different temperature and reaction time on fitting,linear fitting of diffusion control and chemical reaction control model rate was low,and hybrid control model was the highest in 0.92 above,which explained the process of reaction for hybrid control.Activation energy was17.224 kJ/mol had been analyzed by means of experiment.This was further evidence that reaction was the mixture control process of diffusion and chemical reaction. |
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