METHOD FOR OBTAINING CHLORINE LEACHATE FROM PLATINUM GROUP ELEMENT-CONTAINING SOLUTION

• Main Authors: NAKAI TAKAYUKI, SHINGU MASAHIRO, NAGAI HIDEMASA, KURIMOTO KODAI
• Format: Patent
• Language: English; Japanese
• Published: 06.12.2023
• Subjects: CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; METALLURGY; PRETREATMENT OF RAW MATERIALS; PRODUCTION AND REFINING OF METALS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

To provide a method for effectively reducing gold contained in a leachate obtained by chlorine leaching a platinum group element-containing material containing gold as an impunity element, for example, capable of preventing operation efficiency deterioration in a solvent extraction treatment in a post-step.SOLUTION: A method for chlorine-leaching a platinum group element-containing material containing gold as an impurity element and thereafter obtaining a chlorine leachate by solid-liquid separation treatment, includes: a gold reduction step to reduce gold contained in slurry by adding a reducing agent to the slurry with gold concentration of 2.0 g/L or more in a liquid phase, obtained by the chlorine-leaching before the solid-liquid separation treatment; and a solid-liquid separation step to separate the chlorine leachate and a leach residue containing reduced gold precipitates from the liquid after the reduction. The gold reduction step is to control continuously measuring the gold concentration in the liquid phase which is changed by reduction of the gold contained in the slurry, continuing addition of the reducing agent when the gold concentration is 1.8 g/L or more, and stopping the addition of the reducing agent when the gold concentration is less than 1.8 g/L.SELECTED DRAWING: Figure 1 【課題】金を不純物元素として含む白金族元素含有物を塩素浸出して得られる浸出液中に含まれることになる金を効果的に低減し、例えば後工程での溶媒抽出処理の操業効率低下を防ぐことができる方法を提供する。【解決手段】本発明は、金を不純物元素として含む白金族元素含有物を塩素浸出に供し、その後固液分離処理によって塩素浸出液を得る方法であって、塩素浸出により得られた、液相中の金濃度が２．０ｇ／Ｌ以上であるスラリー対して、固液分離処理の前に、還元剤を添加してスラリーに含まれる金を還元する金還元工程と、還元後液から塩素浸出液と還元金の沈澱物を含む浸出残渣とを分離する固液分離工程と、を含む。金還元工程では、スラリーに含まれる金の還元により変動する液相中の金濃度を連続的に測定し、その金濃度が１．８ｇ／Ｌ以上の場合には還元剤の添加を継続し、金濃度が１．８ｇ／Ｌ未満の場合には還元剤の添加を停止する制御を行う。【選択図】図１