(1. 中南大學(xué) 冶金與環(huán)境學(xué)院，長(zhǎng)沙 410083；
2. 中南大學(xué) 難冶有色金屬資源高效利用國(guó)家工程實(shí)驗(yàn)室，長(zhǎng)沙 410083)
摘 要: 應(yīng)用Bromley方程，結(jié)合草酸鈉溶解熱力學(xué)理論及其在水溶液、氫氧化鈉溶液中的溶解度數(shù)據(jù)，得出草酸鈉的Bromley參數(shù)為-0.045，并以此為基礎(chǔ)建立鋁酸鈉溶液中草酸鈉的溶解度計(jì)算模型。應(yīng)用該模型計(jì)算純鋁酸鈉溶液體系中草酸鈉的溶解度，結(jié)果與文獻(xiàn)數(shù)據(jù)吻合較好。在此基礎(chǔ)上，模擬計(jì)算了拜耳法氧化鋁生產(chǎn)過(guò)程中草酸鈉平衡濃度的變化規(guī)律。結(jié)果表明：堿濃度越高、溫度越低、苛性比越高，鋁酸鈉溶液中草酸鈉平衡濃度越低；鋁酸鈉溶液體系中，碳酸鈉、硫酸鈉對(duì)草酸鈉溶解度的影響很小。這些結(jié)果可以解釋草酸鈉在生產(chǎn)氧化鋁過(guò)程中的積累和析出規(guī)律，有助于生產(chǎn)過(guò)程鋁酸鈉溶液中草酸鈉含量的控制。
關(guān)鍵字: 草酸鈉；溶解度；計(jì)算模型；鋁酸鈉溶液
（1. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
2. National Engineering Laboratory for Efficient Utilization of Refractory Non-ferrous Metals Resources,
Central South University, Changsha 410083, China）
Abstract:The calculation model of sodium oxalate’s solubility in sodium aluminate solution was established by Bromley equation with the solubility values of sodium oxalate in the aqueous and sodium hydroxide solution, and Bromley parameter of sodium oxalate calculated by this model is -0.045. Using this calculation model, the solubility values of sodium oxalate in sodium aluminate solution were calculated and a high degree of agreement can be reached compared with the data in literatures. On this basis, the equilibrium concentration values of sodium oxalate in Bayer liquors were calculated. The results show that, the higher the alkali concentration and caustic ratio are or the lower the temperature is, the lower the equilibrium concentration of sodium oxalate is. The concentration of sodium carbonate or sodium sulfate has little effect on the solubility of sodium oxalate. These results can explain the law of the accumulation and precipitation of sodium oxalate in alumina production process, and contribute to controlling the concentration of sodium oxalate in the process.
Key words: sodium oxalate; solubility; calculation model; sodium aluminate solution
