A process for recovering rhodium present in a still heel from the hydroformylation of an unsaturated hydrocarbon wherein rhodium and a triaryl phosphite ligand were used by a process comprising
a) pretreating the still heel with a compatible organic solvent, at least 5 ml of water per 100 g of still heel, oxygen gas or a precursor thereof and sufficient base to produce a pH of 2 to 7 in the reaction mixture after rhodium precipitation;
b) heating to a temperature of from 0° to 80°C to oxidize the triaryl phosphite ligand to the corresponding phosphate compound;
c) heating the mixture from b) for from about 15 minutes to about 120 minutes at about 115°C to about 175°C to precipitate the rhodium and optionally purifying the rhodium from c) by
d) separating the rhodium precipitate;
e) washing the rhodium precipitate with a solvent-acid solution at a pH of to4;
f) treating the rhodium precipitate with an alkaline reducing solution to reduce the trivaient rhodium impurity to zero valent rhodium;
g) quenching the rhodium with glacial acetic acid;
h) separating the rhodium;
i) washing the rhodium with an acid solution at a pH of 3 to 4;
j) drying the rhodium in an inert atmosphere at from 250° to 400°C; and
k) oxidizing the rhodium at a temperature of from 300° to 900°C to convert the rhodium to Rh2O3.
一种回收不饱和烃加氢甲酰化反应生成的静止馏分中的
铑的工艺,其中使用了
铑和三芳基
亚磷酸配体,该工艺包括
a) 用相容的有机溶剂、每 100 克蒸馏
水中至少 5 毫升的
水、
氧气或其前体和足够的碱对蒸馏
水进行预处理,使
铑沉淀后反应混合物的 pH 值为 2 至 7;
b) 加热至 0° 至 80°C 的温度,将三芳基
亚磷酸配体氧化成相应的
磷酸盐化合物;
c) 将来自 b) 的混合物在约 115°C 至约 175°C 的温度下加热约 15 分钟至约 120 分钟,以沉淀
铑,并可选择通过以下方式纯化来自 c) 的
铑
d) 分离
铑沉淀;
e) 用 pH 值为 4 以下的溶剂-酸溶液洗涤
铑沉淀;
f) 用碱性还原溶液处理
铑沉淀,将三价
铑杂质还原为零价
铑;
g) 用
冰醋酸淬灭
铑;
h) 分离
铑
i) 用 pH 值为 3-4 的酸性溶液洗涤
铑;
j) 在 250° 至 400°C 的惰性气氛中干燥
铑;以及
k) 在 300° 至 900°C 的温度下
氧化铑,将
铑转化为 Rh2O3。