Iodoform - crystalline solid lemon yellow with a foul odor. Threshold of feeling the smell 0,000006-0,00027 mg / l, volatile with steam. The melting point of 116-120 0, specific gravity 4.003. In ethanol at 17-18 0 iodoform dissolved 1:75 and 1:10 in the air. It is soluble in acetone, a little - in petrol.
Iodoform production of acetone is reduced to two chemical steps of: obtaining a solution of sodium hypochlorite and getting iodoform using transactions settling, separation, decantation, centrifugation, washing with water, alcohol and drying.
1. Chlorinator stainless steel or enameled. Best of antihlor or monelmetalla equipped with a stirrer, bubbler and a jacket filled with 30% sodium hydroxide solution. Chlorinators can be joined together. On the first pass of the chlorine gas cylinder through the bubbler, and the second is the absorber unabsorbed chlorine. The process is to produce heat. The unit is cooled, preventing the temperature rise above 30 0. At the end of the first chlorination apparatus chlorine is passed in the second and the first is used as an absorber, filling it previously sodium hydroxide. The resulting solution of sodium hypochlorite was adjusted with water to a specific gravity 1,21-1,27.
2. Getting iodoform are in the unit, stainless steel, equipped with cooled brine. There with a solution of sodium hypochlorite and acetone, and from the measuring device to pre-load solution of sodium or potassium iodide. At the beginning of an intense yellow-brown color, which can be observed with an excess of sodium hypochlorite. This is due to the liberation of free iodine, which is totally undesirable, since it leads to the generation, besides iodoform and iodate (passing later in the mother liquor, reducing the output of iodoform and lead to the overhead of expensive sodium iodide).
Recommended that a loading of reactants as follows. Hypochlorite and acetone into the reactor uniformly and at the same time, and the process is conducted with careful stirring and cooling apparatus brine. The reaction temperature should not exceed 10 0. All the while watching the reaction mixture and controls the supply of solutions so that paint was intensely yellow, not brown.
To determine the end of the reaction in the filtrate of the reaction mixture, poured into two test tubes, add: one tube 10-15 drops of a solution of sodium hypochlorite, and in another - 3-5 drops of acetone. If nevypadeniya precipitate iodoform in both tubes reaction was considered complete. This test was repeated in an hour, and then after 30 minutes settling sifoniruyut liquor through a cloth and let down and drains. Technical iodoform after settling, separation and decantation suck in a special decanter - the unit with a mixer, where washed 3-4 times with purified water, and then - with a solution of hydrochloric acid to remove the calcium and iron, and then again washed with purified water and transfer to a centrifuge, where again washed with water, then alcohol. Moist iodoform dried on trays in an oven at 50 kalorifernoy 0. The dry product is screened for elektrovibratsionnom sieve. Packed product in banks orange glass. Screenings are subjected to grinding in a porcelain ball mill [2].
[2]. Maiofis LS Chemistry and technology of chemical and pharmaceutical products. 2nd ed., Rev. and add. - M.: Medicine, 1964. - With. 221-223.
