本文選題：鉛膏預(yù)脫硫 + Na_2SO_4��； 參考：《湘潭大學(xué)》2017年碩士論文

【摘要】：我國(guó)再生鉛企業(yè)目前采用的主要是傳統(tǒng)的鉛膏火法再生工藝,這種處理工藝會(huì)造成嚴(yán)重的環(huán)境污染和資源浪費(fèi)。國(guó)外采用環(huán)保型的濕法脫硫—低溫熔煉工藝,我國(guó)《再生鉛準(zhǔn)入條件》明確規(guī)定“對(duì)分選出的鉛膏必須進(jìn)行脫硫預(yù)處理或送硫化鉛精礦冶煉廠合并處理,脫硫母液必須進(jìn)行處理并回收副產(chǎn)品”,國(guó)家大力推行綠色低碳的鉛膏預(yù)脫硫濕法處理工藝,以年處理15萬噸廢鉛酸蓄電池為例,采用碳酸鈉作脫硫劑,約產(chǎn)生副產(chǎn)物硫酸鈉2萬噸,因此鉛膏預(yù)脫硫副產(chǎn)物硫酸鈉資源化回收顯得尤為重要。本論文針對(duì)鉛膏預(yù)脫硫Na_2SO_4母液的凈化與結(jié)晶工藝進(jìn)行實(shí)驗(yàn)研究。首先,對(duì)于鉛膏預(yù)脫硫Na_2SO_4母液中重金屬(Pb~(2+)、Cd~(2+)、Cu~(2+))和金屬雜質(zhì)離子Fe~(2+)/Fe~(3+)的凈化提出了鐵碳微電解-混凝沉淀的處理工藝,分別進(jìn)行了鐵碳微電解實(shí)驗(yàn)、混凝沉淀實(shí)驗(yàn)和鐵碳微電解-混凝沉淀實(shí)驗(yàn)。在鐵碳微電解-混凝沉淀實(shí)驗(yàn)中,重點(diǎn)研究了停留時(shí)間、鐵碳合金添加量、金屬雜質(zhì)離子初始濃度、pH值、曝氣量等5個(gè)因素對(duì)于Na_2SO_4母液中重金屬和金屬雜質(zhì)離子Fe~(2+)/Fe~(3+)凈化效果的影響。在最佳運(yùn)行條件下,通過鐵碳微電解-混凝沉淀法凈化后,Pb~(2+)、Cd~(2+)、Cu~(2+)、Fe~(2+)/Fe~(3+)的去除率分別為99.2%、99.1%、97.9%、97.3%,Na_2SO_4母液中重金屬和金屬雜質(zhì)離子總含量≤5mg/L。其次,對(duì)于凈化后的Na_2SO_4母液結(jié)晶,本課題組提出了一種基于局部冷卻快速析晶的結(jié)晶新方法。該方法不直接對(duì)儲(chǔ)罐內(nèi)溶液降溫,而是在外循環(huán)的支路上施加冷媒,造成循環(huán)部分流體的快速深度降溫,從而能夠更充分地析出晶體。實(shí)驗(yàn)測(cè)定了不同質(zhì)量分?jǐn)?shù)Na_2SO_4溶液降溫飽和結(jié)晶點(diǎn)溫度,探究了不同質(zhì)量分?jǐn)?shù)Na_2SO_4、最低結(jié)晶溫度對(duì)Na_2SO_4析出率和產(chǎn)品品質(zhì)的影響�？紤]到能耗和經(jīng)濟(jì)效益,本實(shí)驗(yàn)確定最低結(jié)晶溫度為5℃。實(shí)驗(yàn)研究的局部冷卻快速析晶法,能量利用率高,產(chǎn)品析出率高,連續(xù)運(yùn)行,系統(tǒng)簡(jiǎn)單可靠。最后,在廢鉛酸蓄電池再生企業(yè)組建了鐵碳微電解-混凝沉淀+基于局部冷卻快速析晶法回收Na_2SO_4中試實(shí)驗(yàn)裝置,中試實(shí)驗(yàn)采用鉛膏預(yù)脫硫后Na_2SO_4母液,其中Na_2SO_4質(zhì)量分?jǐn)?shù)為16%-28%,處理量為10 m3/h,中試驗(yàn)證了Na_2SO_4母液凈化與結(jié)晶總工藝,中試結(jié)果表明:鐵碳微電解-混凝沉淀+基于局部冷卻快速析晶法對(duì)鉛膏預(yù)脫硫副產(chǎn)物Na_2SO_4母液的凈化與結(jié)晶具有良好的適應(yīng)性,系統(tǒng)運(yùn)行穩(wěn)定,設(shè)備操作簡(jiǎn)單,產(chǎn)品Na_2SO_4品質(zhì)符合國(guó)標(biāo)《GB/T6009-2014》Ⅰ類一等品標(biāo)準(zhǔn),中試產(chǎn)生的冷卻結(jié)晶水滿足前段工藝生產(chǎn)需求,可直接回用。
[Abstract]:At present, the traditional pyrolysis process is mainly used in the lead recycling enterprises in China, which will cause serious environmental pollution and waste of resources. Environmental friendly wet desulphurization and low temperature smelting process have been adopted abroad. In our country, it is clearly stipulated that "desulphurization pretreatment or combined treatment of lead sulfide concentrate smelter must be carried out for the selected lead paste." The mother liquor of desulphurization must be treated and the by-product should be recovered. "the national government has vigorously promoted the green low carbon lead paste pre-desulphurization wet treatment process. Taking 150000 tons of waste lead-acid batteries treated annually as an example, sodium carbonate is used as desulfurization agent. About 20,000 tons of sodium sulfate is produced, so it is very important to recycle the by-product of lead paste. In this paper, the purification and crystallization process of Na _ 2SO _ 4 mother liquor for predesulfurization of lead paste was studied. First of all, for the purification of heavy metals (PB2) and metal impurity ions Fe2 / Fe3 in the Na2SO4 mother liquor predesulfurized by lead paste, the iron-carbon micro-electrolysis and coagulation precipitation processes were put forward, and the iron-carbon microelectrolysis experiments were carried out, respectively, for the purification of heavy metals (Pb ~ (2) and metal impurity ions (Fe ~ (2) / Fe ~ (3). Coagulation precipitation test and iron carbon micro electrolysis-coagulation precipitation experiment. In the experiment of iron-carbon micro-electrolysis and coagulation precipitation, the residence time, the amount of iron and carbon alloy, the initial concentration of metal impurity ion and pH value were studied. The effect of aeration rate on the purification efficiency of heavy metal and metal impurity Fe ~ (2) / Fe ~ (3) in Na2SO4 mother liquor. Under the optimum operating conditions, the removal rates of Fe ~ (2 +) -Fe ~ (2) / Fe ~ (3) in Fe ~ (2 +) -Fe ~ (2) / Fe ~ (3) ratio after purification by iron-carbon microelectrolysis and coagulation precipitation were 99.2 / 99.1 / 97.997. 3% respectively. The total contents of heavy metals and metal impurity ions in Na2SO4 mother liquor were 鈮，

本文編號(hào)：2091410