赤泥中金属镓回收工艺研究

发布时间：2017-12-26 19:04

本文关键词：赤泥中金属镓回收工艺研究　出处：《中北大学》2017年硕士论文　论文类型：学位论文

【摘要】：赤泥是Al_2O_3生产过程中产生的废渣,每生产1t Al_2O_3,产出1~1.8 t赤泥。赤泥堆放占地面积大,对环境污染严重。同时,赤泥中含有大量的有价金属元素,是一种宝贵的二次资源。目前,国内对单独回收赤泥中铁、铝、钛、钪等研究较多,但回收镓的研究较少。本论文分析了赤泥物相组成和化学成分,采用酸浸—萃取(反萃取)—电解工艺从赤泥中富集回收镓,研究结果如下:(1)硫酸常规浸出工艺最佳参数是:浸出温度90℃、硫酸浓度7mol/L、液固比5:1、浸出时间3h。此时,浸出率为89%。恒温熟化预处理过程最佳参数工艺为:熟化温度200℃、熟化时间2h、硫酸浓度4mol/L、液固比2:1。水浸过程最佳参数工艺为:浸出温度70℃、浸出时间60min、加水量20m L。此时,浸出率为93%。盐酸常规浸出工艺最佳参数是:浸出温度100℃、时间4h、盐酸浓度8mol/L、液固比7:1。此时,浸出率为82.07%。硫酸恒温熟化水浸的浸出率比硫酸常规浸出的浸出率高,浸出渣粘度小,过滤的速度快,但是,恒温熟化水浸过程中含氟助浸剂加入量的控制较为严格。(2)微波强化盐酸酸浸工艺最佳参数为:浸出时间25min、浸出温度80℃、液固比7:1、盐酸浓度7mol/L。此时,浸出率为93.46%。超声波强化盐酸酸浸工艺最佳参数为:盐酸浓度8mol/L、浸出温度80℃、液固比7:1、浸出时间15min。此时,镓的浸出率为90.09%。微波强化浸出的浸出率比超声波强化浸出的浸出率高。(3)采用恒温熟化水浸后的浸出液进行萃取实验。以正丙醇为萃取剂,在罗丹明B—正丙醇—硫酸铵体系中进行萃取。萃取过程最佳参数工艺为:硫酸铵质量为4.5g、萃取时间15 min,正丙醇体积分数为30%。此时,镓的萃取率最大为82%。(4)采用微波强化浸出后的浸出液进行萃取实验。以TBP为萃取剂,萃取过程最佳参数工艺为:萃取时间为30 min,TBP体积分数为30%,pH值为5。此时,萃取率最高可达86.34%。以NH_4Cl为反萃剂,最佳工艺参数为:NH_4Cl浓度1.5 mol/L、pH值5.5、反相比2:1。此时,反萃取率达90.34%。(5)对反萃取液进行酸碱中和后进行电解。以铂片为阴极,铂丝为阳极,电流密度为200~300A/m2,槽电压为1.5~1.9V。一般将NaOH浓度控制在130~160 g/L,电解液温度控制在40~45℃左右较适合,电解率可达到48.42%。(6)赤泥中镓的回收率约为36%,酸浸—萃取(反萃取)—电解工艺回收赤泥中镓是可行的。
[Abstract]:Red mud is the waste residue produced in the process of Al_2O_3 production, which produces 1T Al_2O_3 and produces 1~1.8 t red mud. The land area of red mud stacking is large, and it has serious pollution to the environment. At the same time, the red mud contains a large number of valuable metal elements, which is a valuable two resource. At present, many studies have been made on the recovery of iron, aluminum, titanium and scandium in red mud, but there are few studies on the recovery of gallium. This paper analyzes the phase composition and chemical composition of red mud, leaching by acid extraction (extraction) - electrolysis enrichment and recovery of gallium from red mud, the results are as follows: (1) the optimal parameters of conventional leaching process are: sulfuric acid leaching temperature of 90 DEG C, the concentration of sulfuric acid 7mol/L, liquid-solid ratio 5:1, extraction time 3h. At this time, the leaching rate is 89%. The optimum parameters of the pretreatment process are as follows: the curing temperature is 200 c, the curing time is 2h, the concentration of sulfuric acid is 4mol/L, and the ratio of liquid to solid is 2:1. The optimum parameters of the water leaching process are as follows: the leaching temperature is 70, the leaching time is 60min, and the amount of water is 20m L. At this time, the leaching rate is 93%. The optimum parameters of hydrochloric acid leaching process are: the leaching temperature is 100, time 4h, the concentration of hydrochloric acid 8mol/L, and the ratio of liquid to solid to 7:1. At this time, the leaching rate is 82.07%. Sulfuric acid leaching water leaching rate constant temperature curing rate was higher than the conventional sulfuric acid leaching leaching, leaching slag viscosity, filtration speed, but the constant temperature curing flooding control the amount of leaching agent containing fluorine in the process of strict. (2) the optimum parameters of acid leaching process for microwave enhanced hydrochloric acid are as follows: leaching time 25min, leaching temperature 80, liquid solid ratio 7:1, and hydrochloric acid concentration 7mol/L. At this time, the leaching rate is 93.46%. The optimum parameters of acid leaching by ultrasonic enhanced hydrochloric acid are as follows: the concentration of hydrochloric acid is 8mol/L, the leaching temperature is 80, the ratio of liquid to solid is 7:1, and the leaching time is 15min. At this time, the leaching rate of gallium is 90.09%. The leaching rate of microwave enhanced leaching is higher than that of ultrasonic enhanced leaching. (3) the extraction experiment was carried out by the leaching solution after the isothermal ripening of water. The extraction was carried out in the rhodamine B - propanol - ammonium sulfate system with positive propyl alcohol as the extractant. The optimum parameters of the extraction process are as follows: the mass of ammonium sulfate is 4.5g, the extraction time is 15 min, and the volume fraction of positive propanol is 30%. At this point, the maximum extraction rate of gallium is 82%. (4) the extraction experiment of the leaching solution after the leaching of microwave was carried out. With TBP as the extractant, the optimum extraction process is as follows: the extraction time is 30 min, the volume fraction of TBP is 30%, and the pH value is 5. At this time, the maximum extraction rate is up to 86.34%. With NH_4Cl as a stripping agent, the optimum process parameters are as follows: the concentration of NH_4Cl is 1.5 mol/L, the value of pH is 5.5, and the inverse 2:1 is compared. At this time, the rate of reverse extraction is 90.34%. (5) the anti extraction liquid is neutralized by acid base and after electrolysis. Platinum wire is used as cathode, platinum wire is anodic, current density is 200~300A/m2, and slot voltage is 1.5~1.9V. In general, the concentration of NaOH is controlled in 130~160 g/L. The temperature control of electrolyte is suitable at about 40~45 C, and the electrolysis rate can reach 48.42%. (6) the recovery rate of gallium in red mud is about 36%. It is feasible to recover gallium from red mud by acid leaching extraction (reverse extraction) electrolysis process.
【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X758;TF843.1

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