(1. 武漢工程大學(xué) 化學(xué)與環(huán)境工程學(xué)院，武漢 430200；
2. 武漢工程大學(xué) 興發(fā)礦業(yè)學(xué)院，武漢 430000)
摘 要: 風(fēng)化殼淋積型稀土礦原地浸礦中產(chǎn)生大量殘留銨鹽，其緩慢釋放對礦區(qū)周邊環(huán)境造成嚴(yán)重污染，實時測定殘留銨鹽在礦體中的分布對于殘留銨鹽的高效處理意義重大。本文旨在篩選一種快速殘留銨鹽洗脫液，并結(jié)合氨氣敏電極檢測實現(xiàn)風(fēng)化殼淋積型稀土礦中殘留銨鹽的實時檢測。為此，研究了NaCl、KCl、CaCl2、NaOH、KOH、Ca(OH)2、Na2CO3、K2CO3溶液對殘留銨鹽的洗脫過程和脫除率。結(jié)果表明：三種金屬的堿溶液對殘留銨鹽的洗脫速率和效果均高于碳酸鹽和氯化物。在三種堿溶液中，NaOH對殘留銨鹽的洗脫在10 min內(nèi)完成，洗脫率為90%，并且洗脫液無需再經(jīng)pH調(diào)節(jié)，可直接采用氨氣敏電極測定 濃度，方便快捷。采用NaOH洗脫-氨氣敏電極檢測聯(lián)合法可實現(xiàn)稀土礦中殘留銨鹽的高效檢測。
關(guān)鍵字: 風(fēng)化殼淋積型稀土礦；殘留銨鹽；洗脫；實時檢測
（1. School of Chemistry and Environmental Engineering, Wuhan Institute of Technology, Wuhan 430200, China;
2. Xingfa School of Mining Engineering, Wuhan Institute of Technology, Wuhan 430000, China）
Abstract:Large amount of ammonium salt was remained in the weathered crust elution-deposited rare earth ore (WCEDREO) during the in-situ leaching process, and the slow release of these ammonium salt would cause serious pollution to the surrounding environment of the mining area. Real-time detection of the distribution of residual ammonium salt is significant for efficiently treating of the residual ammonium salt. The aim of this paper is to screen a rapid residual ammonium salt eluent and realize the real-time detection of residual ammonium salt in WCEDREO with ammonium gas sensitive electrode. Desorption process and efficiency of the residual ammonium from the WCEDREO by different eluents, including NaCl, KCl, CaCl2, NaOH, KOH, Ca(OH)2, Na2CO3 and K2CO3 solutions, were studied. The results show that alkaline solutions of the three metals have faster elution rates and higher elution efficiencies than those of chloride and carbonate. Among the three alkaline solutions, NaOH solution shows a fast elution process with efficiency of about 90%. Moreover, the concentration of eluted ammonium in the effluent can be conveniently determined by ammonium gas sensitive electrode without further pH adjustment in this system. Based on this investigation, the residual ammonium salt in a rare earth ore can be rapidly determined by the combination method of NaOH elution and ammonium gas sensitive electrode test, which provides basic data for the residual ammonium treatment.
Key words: weathered crust elution-deposited rare earth ore; ammonium salt; eluent; real-time detection
