hi butcher, my english gramer and spell is not clear beacouse i was just pass 10th standerd, so please forgive me if i make mistake. and thanks for your advise for caps off. 4years ago i was done busisnes of purchase in minimum ammount of reject rh.plating solution from jew. ind. per one liter plating bath of fresh when it it contain 2 grams of rhodium 99% present , and it colour is orange red in colour ,after compony used it so many gold ring ,chain,etc. plating with it, after all the plating is not don very well-beacouse plating was start to blacken on jew.so they are rejct the bath, and that time it colour is light yellow,but it have rhodium present of 75% pyority and about 0.650 grams rhodium present in it. Now take 2 liter capacity of plastic contaner- added in 1 liter of rejct plating solution- now added in it 5 pices 0f zinc metal each is 5to 6 grams, and put aside for 24 hours - zinc is precipetate the rhodium as a black powdery form- slidlly vigoruse reaction done between zinc with rhodium sulphate-or chloride. if next day zinc is present and no reaction seen it -prosiger is complit-or there is no zinc present and solution still yellow colour added mor 2 to 3 pices of zinc, after all solution colour water white and zinc now no react-so care fully out zinc , black particals of rhodium 75% wash with planty of water to remove zinc sulphate , and then wet black particals put in 200 ml capacity of bicker and added in 67% NITRIC ACID ONLY 10ML . put it for 12 hours then wash with water- now re wet particals of black rh. added in 4ml of water -4ml of nitric acid 67%-and 15ml of hydro chloric acid 32%,put it cold as it is for 24 hours , decanted, wash with water4 to 5 times and then dry on a stove- only 90 to 100 ounce centigrade- Now it ready for make it grey element form- Take 3inch hight and 1inch diameter of pure carbon moosh- with carbon plate which next put on carbon moosh (stopper)-now put the rhodium bkack inside of the moosh and carbon plate put on it -and all it put in electric furnesh -set 1st cycle of 110 o.cg.for half hour,then 2nd.220 o.cg. and then 1050 ounce only 1 minute and cool it as it in a furness until 35 ounce it cool - out and obeserve it gray element form of rhodium about 95% to 96%pure- your friend ,vinod patel.