本文關鍵詞： 濕法磷酸 白肥 硫酸 磷酸一銨 浸取動力學　出處：《華東理工大學》2015年碩士論文　論文類型：學位論文

【摘要】：白肥是濕法磷酸三段(或兩段)中和法生產(chǎn)飼料級磷酸氫鈣時,一段中和階段得到的固體產(chǎn)物。白肥中P205含量約20-35%,同時富集了濕法磷酸中大部分的Fe、Al、F以及重金屬等雜質(zhì)。白肥中的磷占原料濕法磷酸中總磷的15-30%,但大量雜質(zhì)的富集限制了其應用范圍。白肥的存在,大大制約了飼料級磷酸氫鈣產(chǎn)業(yè)的發(fā)展。為白肥尋找更有效的利用途徑,對磷化工行業(yè)有重要的實際意義。本文以四川某磷化工企業(yè)飼料級磷酸氫鈣工藝中產(chǎn)生的白肥為原料,對其產(chǎn)生過程和組成進行了分析,并根據(jù)其特點,提出了一條以白肥為磷源生產(chǎn)一等品肥料級磷酸一銨的工藝方法：控制適宜的條件,用稀硫酸浸取白肥中的磷；浸取酸與稀磷酸按一定的配比混合后,進行脫氟處理；脫氟后的混合磷酸與液氨反應,通過控制pH值得到磷酸一銨料漿；料漿經(jīng)干燥后即得合格的一等品磷銨。實驗考察了稀酸浸取回收白肥中P205工藝過程,當以最大限度回收白肥中P為目的時,硫酸浸取白肥的最佳條件為：H2SO4/P2O5 (mol)=1.5-1.6,浸取溫度為40～45℃,硫酸濃度為7～8%,白肥粒度小于200目,P的浸取浸取率可達到92%以上；但同時白肥中80%的Al,70%的F以及90%以上的Fe也被浸取。通過控制浸取劑的用量等條件,可以顯著改善浸取的選擇性。當H2SO4/P2O5 (mol)=0.8-1.0時,可以回收70%以上的P；同時白肥中約40%的Fe、Al以及35%左右的F被浸取。浸取的選擇性和磷的浸取率有一定的矛盾,需要根據(jù)具體的工藝需要選擇合適的浸取條件。在浸取工藝研究的基礎上,本文考察了白肥浸取的動力學特性。針對高P浸取率時的浸取反應,建立了浸取動力學數(shù)學模型。
[Abstract]:White fertilizer is used to produce feed-grade calcium hydrogen phosphate by three-stage (or two-stage) wet phosphoric acid neutralization. The content of P205 in white fertilizer is about 20-35, and it has enriched most of the impurities in wet phosphoric acid, such as heavy metal and so on. Phosphorus in white fertilizer accounts for 15-30% of total phosphorus in raw material wet phosphoric acid, but a large amount of impurity is rich. Set limits its scope of application. The existence of white fertilizer, The development of feed grade calcium hydrogen phosphate industry is greatly restricted. It is of great practical significance for the phosphorus chemical industry to find a more effective utilization way for white fertilizer. In this paper, the white fertilizer produced in feed grade calcium hydrogen phosphate process of a phosphorous chemical enterprise in Sichuan is used as raw material. The production process and composition were analyzed. According to its characteristics, a technological method of producing first grade fertilizer grade ammonium phosphate with white fertilizer as phosphorus source was put forward: controlling suitable conditions and leaching phosphorus in white fertilizer with dilute sulfuric acid; After leaching acid and dilute phosphoric acid were mixed according to a certain proportion, the defluorination treatment was carried out, and the mixed phosphoric acid after defluorination reacted with liquid ammonia, which was worth to the monoammonium phosphate slurry by controlling pH. The process of recovering P205 from white fertilizer by dilute acid leaching was investigated. When the maximum recovery of P from white fertilizer was used as the purpose, the optimum conditions for leaching white fertilizer with sulfuric acid were as follows: 1. 5-1. 6% H _ 2SO _ 4 / P _ 2O _ 5 / P _ 2O _ 5, and the leaching temperature was 4045 鈩，

本文編號：1535196