高温焙烧对Pd-Au/SiO_2体系中Pd-Au合金聚集态的影响

以XRD作为主要的表征手段,研究了在Pd-Au/SiO2体系的制备过程中引入高温焙烧技术后对此体系的影响。实验结果表明,制备过程中的还原阶段对Pd-Au合金相的形成起着决定性作用,还原之前的高温焙烧对Pd和Au的化合物产生各自不同的影响,使得Pd,Au不能最终形成均一的合金结构;而还原后的高温焙烧则不影响Pd,Au的合金结构,但会引起金属微粒的凝聚生长,使得晶粒变大,晶粒增长的程度受焙烧气氛、焙烧温度的影响,与焙烧时间无关。

HCl-CuCl_2-NaClO湿法浸取手机元器件中的钯、金

通过HCl-Cu Cl2-Na Cl O湿法浸出体系对手机元器件中金属钯(Pd)、金(Au)进行浸出实验,研究不同因素对于Pd、Au浸出率的影响.结果显示,在2mol/L HCl、体积分数5%Na Cl O、0.075mol/L Cu Cl_2、固液比1%,反应温度60℃条件下,2h后Pd、Au浸出率均可达85%;结果表明,Cu^(2+)、Cl-、温度对于Pd的浸出率起很大作用,Na Cl O的加入可加快Pd浸出反应达到平衡速率;Na Cl O、温度对于Au的浸出率起关键作用,HCl、Cu^(2+)的加入可促进Au的浸出.因此,HCl-Cu Cl_2-Na Cl O湿法浸出体系对于Pd、Au具有良好的浸出效果.

Gold Solubility in SiO_2-HCl-H_2O System at 200℃:a Preliminary Assessment of the Implications of Silicification with Regard toGold Mineralization

The complexation between gold and silica was experimentally confirmed and calibrated at 200℃:Thermodynamic calculations show that AuH3SiO40 would be far more abundant than AnCl2 un-der physicochemical conditions of geological interest, suggesting that silica is much more importantthan chloride as ligands for gold transport. In systems containing both sulfur and silica, AuH3SiO40would be increasingly more important than Au (HS)2 as thc proportion of SiO2 in the system in -creases.The dissolution of gold in aqueous SiO2 soluhons can be described by the reachon:which indicates that SiO2 precipitahon is an effective mechanism governing gold deposihon, and thusexplains the close association of silicification and gold mineralization.