磷尾矿综合利用研究

发布时间：2018-01-02 04:04

本文关键词：磷尾矿综合利用研究　出处：《武汉工程大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着磷矿的不断开采,我国磷矿富矿资源磷匮乏现象凸显。尾矿作为磷矿采矿与选矿过程中产生的一种工业固体废弃物,不论是建库堆积还是作废物抛弃都严重危害到了自然环境,同时还损失了磷尾矿中所含的许多有价值的有效成分。并且随着磷化工行业的不断发展以及磷矿采选的不断进行,堆存在尾矿库中的磷尾矿逐渐增多,原有的尾矿库以无法满足逐渐增多的尾矿量,新建尾矿库势必破坏山林、农田这些生态环境。因此对磷尾矿进行综合利用具有非常明显的现实意义,不仅可以解决环境污染问题而且还能获得二次资源缓解资源匮乏问题。对磷尾矿整体开发利用可以改善生态环境和整治国土,具有巨大的经济、环境和社会效益。本文以云南海口磷矿选矿尾矿为原料,先对其酸浸预处理,得到渣相和滤液。对得到的硅渣进行钠盐煅烧活化-水溶过滤,对水溶物酸化同时加入表面活性剂,过滤洗涤,再煅烧得到白炭黑产品。对酸浸滤液中的有效元素镁、磷进行回收,首先对酸浸液进行酸化除钙,酸化滤液进行两次浓缩得到粗硫酸镁产品,再对粗硫酸镁进行精制;磷通过循环酸浸不断富集,利用复盐结晶法净化湿法磷酸制备磷酸二铵。并利用二乙烯三胺五甲叉膦酸(DTPMP)来进行磷矿脱镁实验,以及磷矿脱镁液回收利用研究。研究结论如下:(1)分别利用XRD、XRF、SEM、TG对高镁磷尾矿进行分析可知:此高镁尾矿主要含有白云石、氟磷灰石、石英和磷石膏;P_2O_5含量10.02%,Mg O含量高达14.5%,可看作是高镁极低品位磷矿;高镁磷尾矿的表面形貌主要为片块状,颗粒大小不均;高镁磷尾矿在600℃之前都保持稳定,600℃-800℃持续失重,此阶段为白云石的分解温度段。(2)为使高镁磷尾矿有较高的磷、镁分解率和回收率,减少磷损失和镁损失,对盐酸分解高镁磷尾矿的工艺路线进行了摸索,得出了最佳的分解条件为投料比2.25、反应温度60℃、反应时间20 min。(3)对高镁磷尾矿酸浸后得到的矿渣分别利用XRD、XRF、BET对酸浸后的矿渣进行分析可知:此高镁尾矿酸浸后白云石和氟磷灰石全部分解,剩余矿渣主要物相为石英和伊利石;二氧化硅含量为78.856%;比表面积、孔径较小,不具备吸附材料的物理特性,需对其进行后处理再用于吸附热性考察。(4)磷尾矿酸浸液提镁工艺条件研究:98%浓硫酸较50%硫酸对酸浸液具有更好的除钙效果;酸化除钙后的滤液一次浓缩比例0.65、二次浓缩比例0.2时得到较高的镁回收率。(5)循环酸解过程酸解液中P_2O_5、Mg O浓度,以及Mg SO_4、CaSO_4的沉淀率都是随着循环次数的增加而逐渐增加的,其中Mg SO_4、CaSO_4的沉淀率经过5次循环后分别达到75.5%、99.8%;浓缩滤液中Mg O浓度随循环次数增加逐渐减小,而P_2O_5浓度是随循环次数增加逐渐增大,经过5次循环后浓缩滤液中P_2O_5浓度达到17%左右,基本达到有机碱复合提取磷酸的要求。(6)按照本文试验流程和工艺操作条件,所得产品,七水硫酸镁达到国家行业标准一等品要求,磷酸二铵符合国家标准优等品要求。(7)进行了磷矿脱镁的研究并确定了最佳工艺条件:直接采用二乙烯三胺五甲叉膦酸进行分解、选择200目原矿进行分解、溶液p H=2、投料比为2.66、反应时间60 min、反应温度70℃。在最佳反应条件下,磷矿脱镁率达到65%以上,磷损失率控制在1.5%以下,经过脱镁处理后的磷矿品位从反应前的25.14%提高到28.89%左右。(8)磷矿脱镁液制备复合阻燃剂产品的过程中,产品A/PER的最佳复配比例为4:1,产品B/ME最佳复配比例为1:3;两种复配阻燃剂在最佳复配比例下质量分数为30%时,阻燃PP,垂直燃烧级别均达到V-0级。本论文的创新之处有以下几点:(1)采用间接硫酸法对磷尾矿进行分解,使硅渣和磷石膏得到较为彻底的分离,得到纯净的硅渣便于对硅的综合利用。酸浸所得渣相和液相均得到有效利用,为无尾矿生产磷矿资源提供理论和试验支持;(2)首次尝试用酸浸硅渣生产白炭黑的可能性,制定的白炭黑符合产品质量标准;(3)首次用循环酸浸-复盐结晶法从高镁磷尾矿中净化湿法磷酸制备磷酸二铵;(4)尝试采用有机酸进行中低品位磷矿脱镁,并将脱镁液制备成磷镁系阻燃剂,实现了镁资源的回收利用。
[Abstract]:With the continuous exploitation of phosphate ore resources, highlighting the phenomenon of lack of phosphorus phosphate in China. As a kind of industrial solid waste tailings mining and beneficiation of phosphate generated in the process, whether it is building or abandoned waste accumulation are serious harm to the natural environment, but also lost a lot of valuable ingredients containing phosphorus in tailings and with the development of phosphorus chemical industry and phosphate mining continued, stockpiling tailings of phosphate tailings in tailings increased gradually, the original cannot satisfy the increasing amount of tailings, the tailings is bound to destroy the new forest, the farmland ecological environment. So it has very obvious practical significance to make a comprehensive utilization phosphate tailings, not only can solve the problem of environmental pollution but also obtain two resources to alleviate the problem of lack of resources. To improve the ecological development and utilization of phosphate tailings overall The environment and land remediation, has great economic, environmental and social benefits. This paper takes Yunnan Haikou phosphate tailings as raw materials, first on the acid leaching pretreatment, slag and filtrate. The obtained silicon slag obtained by calcining sodium - water filtration, the water soluble substances added into acidification surfactants. Filtering and washing, and then calcined silica products. The acid leaching filtrate of elements in magnesium, phosphorus recovery, acidification of first removing calcium acid leaching solution, the filtrate was acidified two times concentrated to obtain crude Magnesium Sulfate products, Magnesium Sulfate for crude and purified by acid leaching cycle; phosphorus enrichment, using salt crystallization purification the preparation of wet process phosphoric acid and diammonium phosphate. By two ethylene three five amino methylene phosphonic acid (DTPMP) to phosphate magnesium removal experiment, and magnesium removal from phosphate rock fluid recycling. The research conclusions are as follows: (1) respectively by XRD, XRF, SEM, TG of the high magnesium The analysis of the high magnesium phosphate tailings tailings containing mainly dolomite, fluorapatite, quartz and phosphogypsum; the content of P_2O_5 10.02% Mg, O content is as high as 14.5%, is considered to be a low grade phosphate rock with high Meiji; surface morphology of phosphate tailings with high magnesium mainly for patches, uniform particle size; phosphate tailings with high magnesium are keep stable at 600 DEG, 600 DEG -800 DEG sustained weight loss, this stage is the decomposition temperature of segment dolomite. (2) the high Mg phosphate tailings have high phosphorus, magnesium decomposition rate and recovery rate, reduce the loss of phosphorus and magnesium loss of process hydrochloric acid decomposition of phosphate tailings with high magnesium content were explored. The decomposition, the best condition for the feed ratio 2.25, reaction temperature 60 C, reaction time of 20 min. (3) to obtain high Mg phosphate tailings after acid leaching slag respectively by XRD, XRF, BET analysis of acid leaching slag: the high magnesium tailings after acid leaching dolomite and fluorapatite All of the remaining slag decomposition, the main phase is quartz and illite; silica content was 78.856%; the specific surface area, pore size is small, does not have the physical properties of adsorption materials, the need for treatment were then used for study of adsorption heat (4). A study on extraction process of magnesium phosphate tailing acid leaching solution: calcium removal effect 98% sulfuric acid has better than 50% sulfuric acid leaching solution; acidification of calcium removal of the filtrate after a concentration ratio of 0.65, two times the concentration ratio of 0.2 mg have a higher recovery rate. (5) cyclic acid hydrolysis process of acid solution in P_2O_5, Mg O, Mg SO_4, CaSO_4 concentration, precipitation rate with the increase of cycle number increases gradually, including Mg SO_4, CaSO_4 precipitation rate after 5 cycles respectively reached 75.5%, 99.8%; Mg O concentration in the filtrate decreases gradually with the increase of cycle times, while the P_2O_5 concentration increases gradually with the increase of cycle times, after 5 cycles After concentrating in the concentration of P_2O_5 reached 17%, basically reached the organic alkali phosphate compound extraction requirements. (6) according to the test process and process conditions, the product, the seven Magnesium Sulfate water to reach the national industry standard grade, diammonium phosphate with the superiority of national standard. (7) studied the removal of magnesium phosphate and the optimum conditions were determined directly by the two: three ethylene amine five methylene phosphonic acid decomposition, choose 200 mesh ore decomposition, solution of P H=2, the feed ratio is 2.66, the reaction time is 60 min, the reaction temperature is 70 DEG C. In the optimum reaction conditions, phosphate magnesium removal rate reached more than 65%, p the loss rate of 1.5% in the control, after removal of magnesium treated phosphate before reaction from 25.14% to about 28.89%. (8) phosphate composite flame retardant products of magnesium removal liquid in the process of product A/PER the best compounding ratio of 4:1, B/ME products The optimal ratio of 1:3; two kinds of flame retardants in the optimal proportion of mass fraction was 30%, the flame retardant PP, verticalburning reaches V-0 grade. The innovations of this paper are as follows: (1) to decompose phosphate tailings by indirect sulfuric acid method, silicon slag and phosphogypsum isolated thoroughly, get the pure silicon slag to facilitate the comprehensive utilization of silicon. The acid leaching slag and liquid phase are available, no tailings to provide the theoretical and experimental support for production of phosphate resources; (2) the first attempt of leaching by acid producing white carbon black silica slag, the silica conforms to the product quality standard; (3) for the first time with cyclic acid leaching salt crystallization method from high magnesium phosphate tailings in purification of wet process phosphoric acid diammonium phosphate; (4) try to use the organic acid low-grade phosphate magnesium removal, and magnesium removal liquid preparation into Linmei flame retardant, the magnesium resource Recycling.

【学位授予单位】：武汉工程大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X754;TD926.4

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