本文選題：鉀長(zhǎng)石礦　切入點(diǎn)：鉀肥　出處：《成都理工大學(xué)》2017年碩士論文

【摘要】：我國(guó)作為全球最大的鉀鹽和鉀肥需求國(guó)之一,鉀肥消費(fèi)量一直大于生產(chǎn)量,鉀肥對(duì)外依附度達(dá)50%左右。合理開(kāi)發(fā)利用國(guó)內(nèi)儲(chǔ)量豐富的難溶性含鉀鹽礦制造鉀肥,積極開(kāi)展提鉀工藝研究,可在一定程度上彌補(bǔ)國(guó)內(nèi)缺乏可溶性鉀鹽資源的不足,緩解我國(guó)鉀肥供需矛盾。鉀長(zhǎng)石是一種自然界分布極廣,我國(guó)儲(chǔ)量極其豐富的難溶含鉀硅酸鹽礦物。本文以四川樂(lè)山峨邊五渡低鉀含量鉀長(zhǎng)石為研究對(duì)象,采用水熱反應(yīng)制備多元素礦物質(zhì)肥料。論文通過(guò)四川樂(lè)山峨邊五渡低鉀含量鉀長(zhǎng)石XRD、XRF分析,確定該礦石主要化學(xué)成分為SiO2、Al2O3、K_2O。物相組成為斜微長(zhǎng)石、石英、鈉長(zhǎng)石。不同粒徑礦石分析結(jié)果表明隨著礦物粒度的減小,硅的含量SiO2的含量在67.90%到69.31%范圍內(nèi)逐漸減少,而K_2O的含量在9.57%到10.19%范圍內(nèi)略有增加,斜微長(zhǎng)石的含量在56.61%到60.27%范圍內(nèi)有增加的趨勢(shì)。礦石K_2O平均含量約為10%。以鉀的溶出率和產(chǎn)物肥料中有效K_2O含量為評(píng)價(jià)標(biāo)準(zhǔn),采用單因素法進(jìn)行了反應(yīng)工藝條件優(yōu)化實(shí)驗(yàn),結(jié)果表明以氧化鈣為助劑,K的溶出率和產(chǎn)物中有效K_2O的含量隨溫度、壓力、液固比、時(shí)間的增大而呈增加的趨勢(shì)。K的溶出率隨CaO用量的增加而增大,產(chǎn)物中有效K_2O含量隨CaO用量增加而呈先增加后減小的趨勢(shì)。溫度、CaO的用量對(duì)K的溶出率和產(chǎn)物中有效K_2O的含量影響均較為顯著。確定工藝條件:以氧化鈣為助劑,Ca/(Si+Al)摩爾比為1.00,液固比僅為1.8∶1,反應(yīng)溫度為250℃,壓力為8Mpa,反應(yīng)時(shí)間20h。水熱反應(yīng)后的產(chǎn)物中鉀的溶出率可到達(dá)85%,產(chǎn)物中K_2O的含量可達(dá)4.76%。產(chǎn)物肥料經(jīng)XRD、XRF、SEM分析可知其主要組成是托貝莫來(lái)石(分子式為Ca5Si6O18·5H2O)和水鈣鋁榴石(分子式為Ca3Al2(Si O4)(OH)8)和斜方硅鈣石(分子式為Ca4Si3O10·2H2O),鉀多以KOH的形式存在。用0.5mol/L鹽酸溶液和蒸餾水作為浸取劑,對(duì)產(chǎn)物中的肥料組分進(jìn)行浸取,由ICP-OES分析結(jié)果可知,產(chǎn)物有效肥料組分分別為:4%可溶性鉀(以K_2O計(jì)量,包括水溶性和枸溶性)、25%枸溶性硅(以SiO2計(jì)量)、44%的枸溶性鈣(以CaO計(jì)量)以及總含量0.4%的枸溶性鐵和鎂以及鋅硼錳等微量元素;實(shí)驗(yàn)考察了產(chǎn)物中鉀的時(shí)間釋放效應(yīng),產(chǎn)物中的水溶性鉀在水中的釋放速率較慢,可能是礦物肥料中鈣、等硅難溶性的組分包裹所致,枸溶性的鉀在酸的作用下釋放速率較快。對(duì)產(chǎn)物外觀特征進(jìn)行了測(cè)定,其疏松堆密度為0.65g/cm3左右,與SEM圖示產(chǎn)物結(jié)構(gòu)疏松,存在大量微米級(jí)孔徑的結(jié)論相符合。產(chǎn)物pH值為11左右,為堿性肥料,適用于酸性土壤,含水量低于0.5%。探討優(yōu)化工藝條件下,鉀長(zhǎng)石礦的分解機(jī)理以及水熱反應(yīng)中各元素存在形式及組成變化。通過(guò)對(duì)不同時(shí)間段的固體反應(yīng)物XRD分析可知,反應(yīng)助劑中的Ca2+交換了鉀長(zhǎng)石中的K+,OH-破壞了鉀長(zhǎng)石的晶體結(jié)構(gòu),由原來(lái)的斜微長(zhǎng)石轉(zhuǎn)變?yōu)檫^(guò)渡態(tài)C-S-H凝膠,C-S-H再轉(zhuǎn)變?yōu)樽罱K的托貝莫來(lái)石和斜方硅石,Al2O3與部分SiO2以及CaO在水熱條件下形成了水鈣鋁榴石。通過(guò)土培實(shí)驗(yàn)得出,產(chǎn)物肥料對(duì)作物肥效明顯,有利于提高產(chǎn)量,并且中和了酸性土壤,有利于根系的生長(zhǎng)。初步驗(yàn)證了產(chǎn)物的肥效。
[Abstract]:China is one of the world's largest salt and potash demand, fertilizer consumption has been greater than the amount of fertilizer production, degree of external dependence is about 50%. The rational development and utilization of abundant domestic potassium salt producing insoluble potash, and actively carry out the research process of potassium, can make up for the lack of domestic shortage of soluble potash resources in some degree, ease the contradiction between supply and demand of China's potash. Potassium feldspar is a very widespread in nature, insoluble potassium silicate minerals rich in reserves in China. This paper takes Sichuan Leshan Ebian five Du low potassium feldspar as research object, by hydrothermal reaction to prepare mineral fertilizers. The Sichuan Leshan Ebian five crossing the low potassium content of potassium feldspar XRD, XRF Al2O3 analysis, determine the main chemical compositions of the ores are SiO2, K_2O., phase composition as microcline, quartz, albite ore. Different particle size analysis results That with the decrease of mineral granularity, SiO2 content of silicon to 69.31% range decreased in 67.90%, and the content of K_2O in the range of 10.19% to 9.57% with a slight increase in microcline in the 56.61% to 60.27% range is increased. The average content of ore is approximately 10% K_2O. With the dissolution of potassium the effective rate and K_2O content in fertilizer products as the evaluation criteria, the reaction conditions are optimized by single factor method. The results show that with calcium oxide as additives, the dissolution rate and the effective content of K_2O in the product with temperature, pressure K, liquid-solid ratio, time increases and increased the release of.K the rate increased with the increase of the content of CaO, K_2O content in the product was first increased and then decreased with increasing CaO content. The temperature, the amount of CaO on the K of the dissolution of the effective content of K_2O rate and the product were more significant. Determine the process conditions were: 姘у寲閽欎負(fù)鍔╁墏,Ca/(Si+Al)鎽╁皵姣斾負(fù)1.00,娑插浐姣斾粎涓，

本文編號(hào)：1685676