If the personal will upon precious metal refining program will produce "will come back" effect! Such as: the choice of ingredients, if you have developed a procedure, choose a reluctant substitute for objective reasons, or the conditional restrictions in the middle of the abandonment of a certain program in the original link, will lead to the failure of refining! Most of this depends on the degree of communication between the employer and the technical side! This is an attitude issue! Now I will write about the refining process of 铑 (only writing rough and refined, not writing refining) The old method of enamel refining: (this is the old international law, but also the classical law): the first step of the separation of ruthenium: the separation of the ruthenium by the reductive hydrolysis method, that is, the commonly used sodium nitrite reduction hydrolysis method, the sputum ( Aluminum solution activated liquid is best) After filtration and concentration, add saturated solution of sodium nitrite while hot, and make the sputum completely change to light color and transparent (reduced thoroughly), add saturated sodium hydroxide solution to make PH=9.26 cool. Set for 30 minutes, then the precious metal [partial palladium , all platinum , all bismuth, all 铱 (when gold, bismuth , bismuth should be separated in advance, see my blog)] will not form alkali precipitation! The base metal is hydrolyzed and precipitated in addition to cobalt ! The precipitate was filtered off, and the precipitate was washed three times with water of pH=9.3. The washing water and the filtrate were combined and acidified to pH=2 with hydrochloric acid, and then the above steps were carried out, and finally the whole filtrate and the washing liquid were collected and combined (commonly known as two Secondary liquid). The filter residue contains a part of palladium for palladium! The second step of palladium separation: separation of palladium with diacetyl ketone, the second precious liquid concentrated hydrogen peroxide nitroxylene completely and adjusted PH = 2, adding dimethylglyoxime solution, so that palladium is bright yellow dipyridamole palladium precipitation , heating to 70 degrees to make it heat, filter, the filtrate is then oxidized to dark color with hydrogen peroxide, the platinum is separated from the hydrazine by hydrolysis, the slag is filtered off, washed with water of pH 8.5 and acidified with hydrochloric acid to filter residue. Just completely dissolved, heat the solution to 80 degrees! Add 10% sodium sulfide solution at pH=4.5, so that most of the antimony forms a barium sulfide precipitate! It can reduce the enthalpy to the range of the next step of ammonium sulphide removal (but 30% is also dispersed in the precipitate)! After the hydrazine main body liquid is hydrolyzed (mainly desulfurized), it is filtered out of yttrium yellow (strontium hydroxide) and then acidified, refined by ammonium sulfide, reduced with hydrazine hydrate, washed, and then purified by hydrofluoric acid to obtain pure strontium powder. . The new method of refining (the famous method of refining Chinese sturgeon): the first step (solution without gold or palladium, extraction with S201 or diisooctyl sulfide when gold palladium is contained, or removal of gold with sulfurous acid, In addition to palladium dimethylglyoxime, subsequent oxidation continued): distinction or separation: rhodium was adjusted to make a good PH = 1.5, with a 30% P204 [di (2-ethylhexyl) phosphate] + 70% n-dodecane extraction of copper base metal, such as aluminum kovar. (Note: the diluent must be n-dodecane!!) until the extracted oil phase does not change color (maybe eight to ten stages of extraction is not yet), the raffinate needs to be oxidized with hydrogen peroxide and the acidity is adjusted to 4 moles ( Detection with analytical grade base). The second step is to separate from the noble: extract the adjusted raffinate with 30% TRPO (C7-C9) + No. 4 solvent oil, and extract until the oil phase does not change to (may be six to eight levels of extraction)! A series of extracted mashes are adjusted to pH=9, so that the yttrium is precipitated by yttrium (separating residual organic matter and residual organic phase). After washing, the hydrazine is reduced with hydrazine, and then hydrogen is reduced to pure after boiling with hydrofluoric acid. rhodium. It is necessary to have special extraction equipment to support the whole process! The new method of refining 铑 has a high recovery rate! Very pure!

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