溴化物溶液中活性炭吸附金的研究

Studies on adsorption of gold on activated carbon in bromide solution

用活性炭可从含金溴化物溶液中吸附金。在室温（２０～３５℃）；Ｃ：Ａｕ＝０．７ｇ：１ｍｇ；溶液ｐＨ＜６，溶液中溴化钠浓度小于０．２ｍｏｌ．Ｌ－１；适当搅拌下；吸附４ｈ，金吸附率可达９５％以上。吸附反应为溶液中金扩散过程所控制。－ｄｃ／ｄｔ＝ｋｃ，ｋ≈０．０３５３ｍｉｎ－１。吸附等温线可用朗格缪尔公式表示ｑ＝ｑａｃ／（１＋ａｃ），ｑ≈３３５ｍｇ·ｇ－１，ａ≈０．０５６２Ｌ．ｍｇ－１。金以元素金状态吸附在活性炭上。用离子交换以及金离子在活性炭表面上被还原的反应历程可解释大部分实验现象。

Gold in bromide solution can be adsorbed by activated carbon.Oncondition that at room temperature (20--35℃). C: Au = 0.7g: 1mg, pH<6, sodiumbromide concentration<0 .2mol. L-1 .,suitable agitation for 4 hr, An adsorptionrate can reach to more than 95 %. Adsorption reaction is controlled by diffusionprocess of gold in solution. - dc/dt ≈kc, k is about 0.0353 min-1. Adsorptionisotherm can be expressed by Langmuir formula, q = q ac/(1 + ac), q is about 335mg g-1,a is about 0.0562 L.mg-1.The gold is in a state of element to be adsorbedonto activated carbon These experimental phenomena can be explained with ionexchange and reduction process of gold ion on the surface of activated carbon.