本文選題：鋁電解槽廢舊陰極 + 氟化物��； 參考：《西安建筑科技大學(xué)》2015年碩士論文

【摘要】：隨著我國(guó)電解鋁產(chǎn)量的大幅度提高,鋁電解槽每年排放的廢舊陰極材料也隨之逐年增長(zhǎng)。廢舊陰極中含有大量的可溶氟化物,屬于危險(xiǎn)固體廢棄物。露天堆放或直接填埋時(shí),會(huì)對(duì)周圍生態(tài)環(huán)境造成嚴(yán)重污染。同時(shí),其中含有的氟化物會(huì)對(duì)浮選工藝產(chǎn)生嚴(yán)重的影響。因而提出先浸出,后浮選的工藝,去除其中可溶氟化物,使其由危險(xiǎn)固廢轉(zhuǎn)化為一般固廢,以優(yōu)化浮選工藝。所以,研究廢舊陰極處置過(guò)程中F-的遷移規(guī)律,具有重要的理論和應(yīng)用價(jià)值。本文所用原料取自山西運(yùn)城某鋁電解生產(chǎn)企業(yè)大修期間新拆卸的鋁電解槽廢舊陰極材料,通過(guò)礦相分析、XRD檢測(cè)以及元素分析等多種手段,充分了解其主要組成部分,分析其中氟化物的存在形式。通過(guò)對(duì)其進(jìn)行粗碎、細(xì)碎、浸出后,得到較優(yōu)的浸出實(shí)驗(yàn)條件,同時(shí)對(duì)其浸出含氟廢水進(jìn)行無(wú)害化處理。浸出之后,對(duì)于浸出渣,可作為非危險(xiǎn)固體廢棄物直接排放,也可通過(guò)浮選工藝進(jìn)行分選,最終對(duì)浮選精礦進(jìn)行回收利用。通過(guò)實(shí)驗(yàn)研究,主要得出以下結(jié)論:(1)鋁電解槽廢舊陰極材料主要以C、Na3AlF6、NaF、CaF2等形式存在,其中碳含量高達(dá)68.58%,其余為電解質(zhì),且氟化物主要以Na3AlF6、CaF2、NaF三種形式存在,其中常溫下NaF為主要的可溶氟化物。(2)較優(yōu)浸出實(shí)驗(yàn)條件為:浸出劑為水,粒徑為0.075~0.096mm,液固比為55:1,浸出溫度為85℃,浸出時(shí)間為2h。其中可溶F-最大浸出量為11.25%,占理論可溶F-的97.8%。(3)浸出渣XRD檢測(cè)分析結(jié)果表明:廢舊陰極中的NaF已經(jīng)基本全部溶解到溶液中,此時(shí)浸出渣中的F-可以控制在危險(xiǎn)固體廢棄物限制的含量以內(nèi),可予以排放,也可通過(guò)浮選工藝進(jìn)行回收利用。(4)對(duì)其浸出高濃度含氟廢水進(jìn)行處理,實(shí)驗(yàn)結(jié)果表明:采用CaCl2沉淀法和硫酸鋁沉淀法可將可溶F-濃度降到10mg/L以下,達(dá)到國(guó)家廢水排放標(biāo)準(zhǔn),最高可溶F-脫除率均為99.5%,但前者最終溶液顯中性,后者顯酸性;而CaO沉淀法和超濾法均無(wú)法處理達(dá)標(biāo)。綜合對(duì)比,采用Ca Cl2沉淀法處理含氟廢水為最佳處理實(shí)驗(yàn)方法。(5)對(duì)于浮選后的精礦,采用在原廠陰極中適量添加的方法進(jìn)行回收利用。實(shí)驗(yàn)結(jié)果表明:在原廠陰極中加入20%的瀝青和適量浮選精礦,經(jīng)過(guò)焙燒后,其電阻率明顯增長(zhǎng),且可以達(dá)到使用標(biāo)準(zhǔn)。同時(shí),浮選精礦不宜配入過(guò)多,否則電阻率會(huì)超出陰極使用的規(guī)定范圍。本研究結(jié)果對(duì)廢舊陰極的儲(chǔ)運(yùn)、選分、提純以及廢水處理等均具有參考價(jià)值。
[Abstract]:With the increase of electrolytic aluminum production in China, the waste cathode material discharged by aluminum reduction cell increases year by year. The waste cathode contains a large amount of soluble fluoride, which is a hazardous solid waste. Open-air stacking or direct landfill will cause serious pollution to the surrounding ecological environment. At the same time, the fluoride contained therein will have a serious effect on the flotation process. Therefore, the process of leaching first and then floatation is put forward to remove soluble fluoride from dangerous solid waste to general solid waste in order to optimize flotation process. Therefore, it is of great theoretical and practical value to study the law of F- migration in the process of waste cathode disposal. The raw materials used in this paper are taken from the waste cathode material of aluminum electrolytic cell that was newly disassembled during the overhaul of an aluminum electrolysis production enterprise in Yuncheng, Shanxi Province. The main components of the material are fully understood by means of phase analysis, XRD detection and element analysis, etc. The existing forms of fluoride were analyzed. After coarse, fine and leaching, the optimum leaching conditions were obtained, and the wastewater containing fluorine was treated innocuously at the same time. After leaching, the leachate slag can be directly discharged as non-hazardous solid waste, or can be separated by flotation process, and the flotation concentrate can be recycled. The main conclusions are as follows: (1) the waste cathode materials of aluminum reduction cell mainly exist in the form of Con Na 3AL F 6 and NAF F 2, in which the carbon content is as high as 68.58%, the rest is electrolyte, and the fluoride mainly exists in three forms, Na 3AL F 6, CaF 2N NAF, etc. The optimum leaching conditions are as follows: the leaching agent is water, the particle size is 0.075 渭 m, the liquid-solid ratio is 55: 1, the leaching temperature is 85 鈩，

本文編號(hào)：1902967