本文選題：α半水石膏 + 鈦白廢酸�。� 參考：《鄭州大學(xué)》2015年碩士論文

【摘要】：目前,鈦白粉生產(chǎn)主要有硫酸法、鹽酸法以及氯化法。由于硫酸法技術(shù)成熟,國內(nèi)絕大部分鈦白粉廠多采用此法。據(jù)統(tǒng)計(jì)每生產(chǎn)1t鈦白粉會(huì)產(chǎn)生廢酸8~10t。廢酸中含有20%左右的硫酸和10%左右硫酸亞鐵以及大量鈦鹽,回收利用難。多采用石粉常溫下中和,產(chǎn)物多為二水石膏,由于雜質(zhì)含量較多,通常被用作堆埋處理,既浪費(fèi)資源,又污染環(huán)境。本文以鈦白廢酸和石粉(或石灰乳)為原料,利用雙加法和常壓鹽溶液法制備α半水硫酸鈣,主要研究了溫度、漿料濃度、p H等工藝參數(shù)和轉(zhuǎn)晶劑對(duì)產(chǎn)物晶體形貌的影響。研究內(nèi)容主要包括以下幾個(gè)方面:1)以鈦白廢酸和石灰乳為原料,利用雙加法,通過在母液中加入轉(zhuǎn)晶劑、控制反應(yīng)溫度、進(jìn)料速度、廢酸稀釋倍數(shù)以及其他工藝參數(shù),從而制備出晶形良好的α半水石膏。但是大量的實(shí)驗(yàn)證實(shí),雙加法(酸化法的一種)更適合制備長徑比大的α半水石膏晶須,不能制備出大的、短柱狀的α半水石膏。2)研究了鈦白石膏在常壓Ca Cl2-Mg Cl2-KCl溶液中的轉(zhuǎn)化過程。討論了溫度、漿料濃度、鹽濃度、溶液p H以及轉(zhuǎn)晶劑對(duì)產(chǎn)物α-HH(α半水石膏)的影響。結(jié)果表明,溫度98℃,鹽濃度25%,漿料濃度20%,p H=4.5,轉(zhuǎn)晶劑添加量為0.01%時(shí),能制備出粒徑相對(duì)統(tǒng)一,長徑比接近1:1的α-HH,標(biāo)稠需水量為0.35時(shí),測(cè)得絕干抗壓強(qiáng)度為32.6Mpa。3)研究了鈦白石膏在常壓Na Cl溶液中的轉(zhuǎn)化過程。討論了溫度、漿料濃度、鹽濃度、溶液p H以及轉(zhuǎn)晶劑對(duì)產(chǎn)物α-HH的影響。結(jié)果表明,溫度在98℃,鹽濃度15%,漿料濃度20%,p H=2.5,轉(zhuǎn)晶劑添加量為0.5%時(shí),能制備出長徑比約為1:1的短柱狀α-HH,標(biāo)稠需水量為0.33時(shí),測(cè)得48h絕干抗壓強(qiáng)度為35.2Mpa。
[Abstract]:At present, titanium dioxide production mainly includes sulfuric acid, hydrochloric acid and chlorination. Due to the maturation of sulfuric acid process, most titanium dioxide plants in China adopt this method. According to statistics, each production of 1 ton of titanium dioxide will produce 8 tons of waste acid 10 t. The waste acid contains about 20% sulfuric acid, about 10% ferrous sulfate and a large amount of titanium salt, so it is difficult to recycle. Most of them are neutralized by stone powder at room temperature, and the products are gypsum dihydrate. Because of the high impurity content, it is usually used as a heap disposal, which not only wastes resources, but also pollutes the environment. In this paper, 偽 -hemihydrate calcium sulfate was prepared from titanium dioxide waste acid and stone powder (or lime milk) by double addition method and salt solution under normal pressure. The effects of temperature, slurry concentration, pH and transgranular agent on the crystal morphology of the product were studied. The main contents of the research include the following aspects: (1) using titanium dioxide waste acid and lime milk as raw materials, by adding transgranular agent into mother liquor, controlling reaction temperature, feed rate, dilution ratio of waste acid and other technological parameters. Thus, 偽-hemihydrate gypsum with good crystal shape was prepared. However, a large number of experiments have proved that the double addition method (one of the acidizing methods) is more suitable for the preparation of 偽 -hemihydrate whiskers with large aspect ratio. Short columnar 偽 -hemihydrate gypsum. 2) the conversion process of titanium dioxide gypsum in atmospheric pressure Ca Cl2-Mg Cl2-KCl solution was studied. The effects of temperature, slurry concentration, salt concentration, solution pH and transgranular agent on the product 偽 -HH (偽 -hemihydrate gypsum) were discussed. The results show that when the temperature is 98 鈩，

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