Wuhan Kaidi Engineering Technology Research Institute Co., Ltd.

Sunshine Kaidi New Energy Group Co., Ltd.

Yiming Han

Dechen Song

Li Xu

Qianqian Liu

Bo Lai

A method for recovering ruthenium from a spent ruthenium-based catalyst carried on aluminum oxide includes: drying, calcining, and cooling a spent catalyst; grinding the spent catalyst into black powder; placing the black powder in a fluidized bed reactor, purging the reactor with hydrogen and heating the black powder to obtain ruthenium metal, then heating the black powder in a mixed atmosphere of oxygen and ozone to obtain RuOgas; absorbing the RuOgas with a sufficient amount of hydrochloric acid to obtain a HRuClsolution; adding an excess oxidant to the HRuClsolution to oxidize the HRuClinto HRuCl; adding excess NHCl to the HRuCland then filtering, and washing the filter cake to obtain solid (NH)RuCl; and reducing the solid (NH)RuClby hydrogen to obtain ruthenium metal.

Method for recovering ruthenium from spent ruthenium-based catalyst carried on aluminum oxide

A method for preparing solid ruthenium nitrosyl nitrate, including: 1) drying a ruthenium-containing spent catalyst, and calcining the spent catalyst, and cooling to room temperature, whereby yielding a ruthenium-containing solid; 2) grinding the ruthenium-containing solid to yield a powder, introducing the powder to a fluidized bed reactor, aerating the fluidized bed reactor with nitrogen or an inert gas, charging hydrogen, whereby yielding ruthenium metal; 3) contacting a mixed gas of ozone and air with the ruthenium metal, whereby yielding gaseous ruthenium tetroxide; 4) introducing the gaseous ruthenium tetroxide into a three-stage absorption plant, whereby yielding an acid solution including ruthenium nitrate; 5) adding a solid of sodium nitrite to the acid solution, stirring, and heating a resulting solution, whereby yielding a solution of ruthenium nitrosyl nitrate; and 6) extracting the solution of ruthenium nitrosyl nitrate with anhydrous ether.

Method for preparing solid ruthenium nitrosyl nitrate

A method for preparing crystalline cobalt nitrate. The method includes: 1) calcining a spent Co/SiOcatalyst, cooling the calcined material to room temperature, and grinding it to yield a powder; 2) heating the powder in a fluidized bed reactor; 3) adding the heated powder into excess dilute nitric acid solution and filtering to obtain a cobalt nitrate solution; 4) adjusting the pH value of the cobalt nitrate solution to 1.5, adding a preheated oxalic acid solution, adjusting a pH value of the resulting solution to 1.5, immediately filtering the resulting solution to yield a precipitate of cobalt oxalate, washing the precipitate of cobalt oxalate to yield a neutral filtrate; 5) drying the precipitate and calcining to yield cobalt oxide; 6) dissolving the cobalt oxide in nitric acid to yield a second cobalt nitrate solution; and 7) evaporating the second cobalt nitrate solution to obtain crystalline cobalt nitrate.

Method for preparation of high purity, crystalline cobalt nitrate from spent cobalt/silica catalyst

A method for recovering cobalt, ruthenium, and aluminum from spent Co&#x2014;Ru/AlOcatalyst. First, Co&#x2014;Ru/AlOspent catalyst is subjected to hydrocarbon removal, reaction with hydrogen, and alkali fusion to obtain a slag. The slag is subjected to acid leaching, precipitation of cobalt with oxalic acid or ammonium oxalate, reduction of cobalt oxalate, and dissolution of cobalt metal with nitric acid to obtain Co(NO).6 HO. The effluent of acid leaching is subjected to reaction with ethanol, filtration to obtain a filtrate and residue, dissolution of the residue with concentrated hydrochloric acid, and vacuum distillation to obtain &#x3b2;-RuCl.x HO. Aluminum hydroxide is prepared from the filtrate through carbonation and calcination. The cobalt yield is &#x2267;97%; the ruthenium yield is &#x2267;95%, and the aluminum yield is &#x2267;92%.

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Wuhan, China

Yiming Han