【摘要】：本文主要開展兩個方面工作：(1)在實(shí)驗(yàn)室小試的基礎(chǔ)上對鉀長石-磷礦-硫酸體系機(jī)械力化學(xué)法提鉀技術(shù)進(jìn)行中間試驗(yàn),對自行設(shè)計(jì)制作的設(shè)備性能進(jìn)行評估；(2)采用熱分解法對氟化學(xué)酸解鉀長石工業(yè)化產(chǎn)物鉀明礬制備氧化鋁和硫酸鉀進(jìn)行研究,探究其最佳工藝流程；并通過TG-DSC熱分析曲線研究鉀明礬分解行為和分解過程動力學(xué)。中間試驗(yàn)一個周期連續(xù)運(yùn)轉(zhuǎn)3.25h可得150kg產(chǎn)物,產(chǎn)品中有效氮、磷、鉀總量占10%左右,鉀長石和磷礦的分解率分別達(dá)到39.84%和58.10%,并且產(chǎn)品中未完全分解的鉀長石與磷礦在土壤環(huán)境中也會繼續(xù)緩慢釋放鉀、磷元素,形成長期有效地緩釋效果。適當(dāng)?shù)奶妓釟滗@不僅可以控制pH使產(chǎn)物中鋁離子完全沉淀,而且所得產(chǎn)物為干燥粉末狀。中間試驗(yàn)達(dá)到了預(yù)期目標(biāo),產(chǎn)品效果良好,驗(yàn)證了工藝流程的可靠性和穩(wěn)定性,為進(jìn)一步擴(kuò)大生產(chǎn)提供了一些參考設(shè)計(jì)數(shù)據(jù)。以鉀長石制備的鉀明礬為原材料,通過熱分解法由鉀明礬制備氧化鋁和硫酸鉀,提純后,采用焙燒-水浸工藝對鉀明礬進(jìn)行分解,制取硫酸鉀和氧化鋁,實(shí)驗(yàn)表明其最佳工藝條件為：焙燒溫度為850℃、時間為20min,焙燒產(chǎn)物水浸分離鉀、鋁,水浸溫度100℃、固液比1/5 g/mL、時間20min。濾餅干燥得氧化鋁,濾液蒸發(fā)結(jié)晶得硫酸鉀。氧化鋁總收率86.52%,硫酸鉀總收率85.02%,氧化鋁純度98.52%符合GB/T 24487-2009氧化鋁標(biāo)準(zhǔn),硫酸鉀中K2O含量47.85%符合GB 20406-2006農(nóng)用硫酸鉀標(biāo)準(zhǔn)。通過TG-DSC同步熱分析探討鉀明礬的分解過程,并用XRD檢測生成物,可得出鉀明礬熱分解動力學(xué)反應(yīng)級數(shù)為一級反應(yīng),熱失重過程可分為兩步脫去結(jié)晶水反應(yīng)以及復(fù)鹽中硫酸鋁熱分解反應(yīng)三個階段,生成氧化鋁以α-氧化鋁形式存在。
[Abstract]:This paper mainly carried out two aspects of the work: (1) on the basis of the laboratory test, the potassium feldspar phosphate rock-sulfuric acid system mechanochemical process potassium extraction technology was carried out in the intermediate test, and the performance of the equipment designed and made by ourselves was evaluated; (2) the preparation of alumina and potassium sulfate from potassium alum, a commercial product of potassium feldspar, was studied by means of thermal decomposition, and the optimum technological process was explored. The decomposition behavior and kinetics of potassium alum were studied by TG-DSC thermal analysis curve. The 150kg products can be obtained by continuous operation of 3.25h in a period of 3.25h. The total amount of available nitrogen, phosphorus and potassium in the product is about 10%. The decomposition rates of potassium feldspar and phosphate rock are 39.84% and 58.10%, respectively. And the potassium feldspar and phosphate rock which are not completely decomposed in the product will release potassium and phosphorus slowly in soil environment and form a long-term effective slow-release effect. The proper ammonium bicarbonate can not only control pH to precipitate aluminum ions completely, but also produce dry powder. The intermediate test achieved the expected goal and the product effect was good. The reliability and stability of the process were verified and some reference design data were provided for the further expansion of production. Potassium alum prepared from potassium feldspar was used as raw material to prepare alumina and potassium sulfate from potassium alum by thermal decomposition. After purification, potassium alum was decomposed by roasting-water leaching process to produce potassium sulfate and alumina. The results show that the optimum technological conditions are as follows: calcination temperature 850 鈩，

本文編號：2404469