Preparation of sodium thioantimonate (sodium sulfoantimonate)
Sodium sodium thioantimonate can be prepared from antimony trisulfide by the combined action of a solution of sodium sulfide and sulfur. Sodium thioantimonate crystallizes well with nine molecules of water – Na3SbS4 · 9H2O. The hydrolysis of this salt, which produces a dirty appearing reddish brown precipitate consisting of an indefinite mixture of Sb2S5 and Sb2O5, may be prevented by an excess of sodium sulfide or by the presence of sodium hydroxide.
67 grams of finely powdered antimony trisulfide (stibnite), 140 grams of sodium sulphide nonahydrate (or 47 grams of anhydrous sodium sulfide and an additional 93 ml of water) and 13 grams of powdered sulfur are mixed and added to a casserole containing 150 ml of water. The mixture is heated and kept at the boiling temperature for 15 minutes. The obtained solution is filtered the residue is rinsed with hot water containing a little sodium hydroxide, by bringing up the volume of the solution to 250 ml. While still hot the filtrate is let to crystallize. After the solution cools the obtained crystals are filtered, the mother liquor is evaporated yielding a second crop of crystals. If there is any tendency for a muddy brownish precipitate to form in the solution, or for the same substance to form as a scum on the crystals, a little amount of 6 N (~15%) NaOH is added to the solution and the crystals are treated in it. The crystals are spread on paper towels, and as soon as they are dry, transferred in a stoppered bottle.
Synthetic inorganic chemistry, by A. A. Blanchard, 310-311, 1936
43 g of powdered antimony trisulfide are ground thoroughly in a mortar with 43 g of anhydrous sodium sulfate and 16 g of charcoal. The mixture is placed in a large clay crucible (the latter should be about half-filled), covered with a thin layer (about 1/8 inch) of charcoal and heated over a Meker burner to a state of quiet fusion, then ten minutes longer. The melt is poured into an iron dish, allowed to cool and then powdered. The material is then boiled under reflux with 7 g of sulfur powder in 300ml of water, until all the sulfur has dissolved. The solution is evaporated on the steam bath to crystallization and crystal crops isolated without washing. The final mother liquor is heated to dryness on the water bath, and the entire crude product is recrystallized from an equal weight of boiling water containing a little (about 0.5g) sodium hydroxide. More product is isolated from the filtrate by the addition of alcohol and the material is dried in vacuo over lime. Pale yellow crystals. Yield 75 g.
Inorganic laboratory preparations, by G. G. Schlessinger, 69, 1962
SODIUM THIOANTIMONATE, CTK4C0967, GJJDHSBABFZVRQ-UHFFFAOYSA-N, Antimonate(3-),tetrathioxo-, sodium (1:3), (T-4)-, 13776-84-6