《湿法冶金过程及设备培训》-浸出过程的化学反应重难点答疑

湿法冶金过程化学反应重难点答疑Q&AonKeyandDifficultQuestionsofChemicalReactionsinHydrometallurgicalProcess一、常见重点问题答疑I.AnswerstoFrequentlyAskedKeyQuestions1.闪锌矿氧压浸出的反应方程式是什么？反应中硫元素的价态如何变化？1.Whatisthereactionequationforoxygenpressureleachingofsphalerite?Howdoesthevalencestateofsulfurelementchangeinthereaction?解答：反应方程式为ZnS+H₂SO₄+½O₂→ZnSO₄+S+H₂O。硫元素价态由ZnS中的S²⁻（-2价）氧化为单质硫S⁰（0价）。Answer:ThereactionequationisZnS+H₂SO₄+½O₂→ZnSO₄+S+H₂O.ThevalencestateofsulfurelementisoxidizedfromS²⁻(-2valence)inZnStoelementalsulfurS⁰(0valence).2.锌焙砂酸浸和金矿氰化浸出的温度控制要求分别是什么？原因是什么？2.Whatarethetemperaturecontrolrequirementsforzinccalcineacidleachingandgoldorecyanideleaching?Why?解答：锌焙砂酸浸需控制温度在80-90℃，原因是提高反应速率（温度每升高10℃，反应速率提高2倍）；金矿氰化浸出需在常温下进行，原因是避免HCN挥发带来的安全与环保问题。Answer:Thetemperatureofzinccalcineacidleachingneedstobecontrolledat80-90°Ctoincreasethereactionrate(forevery10°Cincreaseintemperature,thereactionrateincreasesby2times);goldorecyanideleachingneedstobecarriedoutatroomtemperaturetoavoidsafetyandenvironmentalprotectionproblemscausedbyHCNvolatilization.二、常见难点问题答疑II.AnswerstoFrequentlyAskedDifficultQuestions1.金矿氰化浸出中络合物[Au(CN)₂]⁻的生成机理是什么？其稳定性如何体现？1.Whatistheformationmechanismofcomplex[Au(CN)₂]⁻ingoldorecyanideleaching?Howisitsstabilityreflected?解答：机理是Au0与CN-通过配位键结合形成稳定络离子[Au(CN)2]⁻。其稳定性通过稳定常数（K稳≈2×1038）体现，高稳定常数确保金能从矿石中高效溶解进入溶液。Answer:ThemechanismisthatAu0andCN-combinethroughcoordinationbondstoformastablecomplexion[Au(CN)2]⁻.Itsstabilityisreflectedbythestabilityconstant(Kstability≈2×1038),andthehighstabilityconstantensuresthatgoldcanbeefficientlydissolvedfromtheoreintothesolution.2.硫酸体系浸出中为何需控制pH在1.5-2.0？若pH异常应如何处理？2.WhyshouldthepHbecontrolledat1.5-2.0duringsulfuricacidsystemleaching?WhatshouldbedoneifthepHisabnormal?解答：控制pH在1.5-2.0的原因是防止Fe³⁺水解生成沉淀，避免影响浸出效率和后续净化工序。若pH异常，可通过添加石灰调节至目标范围，确保体系稳定性。Answer:ThereasonforcontrollingthepHat1.5-2.0istopreventFe³⁺fromhydrolyzingtoformprecipitateandavoidaffectingleachingefficiencyandsubsequentpurificatio