JSC “Chelyabinsk Zinc Plant”, Chelyabinsk, Russia:

O. A. Fatkhutdinova, Leading Production Engineer of Engineering Center, e-mail: oaf@zinc.ru

A. V. Zatonskiy, Technical Director
P. A. Kozlov, Head of Engineering Center

LLC “UMMC-Holding”, Verkhnyaya Pyshma, Russia:

A. M. Panshin, Technical Director

This paper discusses the results of research, carried out on pilot zinc production waste water treatment unit. The first stage of the pilot trials is chemical treatment of waste waters (using reagents) and their concentration on reverse osmosis unit. Deficiency of sulphurous zinc materials shows the need to engage recycled material in processing. During recycling process, secondary raw materials are cleaned from impurities derived by sewage. Chlorides, sulfates and sodium fluorides are the main impurities removed by sewage. Standard limestone technology of waste water treatment does not give the possibility to remove the foregoing soluble impurities from waste waters. Return of waste waters to the process is not possible owing to the harmful effect of sulphates, chloride and fluoride on the process of zinc extraction. Developed technology of waste water treatment allows to use the purified water in industrial production and direct the concentrate acquired from reverse osmosis to evaporation. Optimal conditions and parameters of the following processes are defined:
– chemical treatment of waste water (adding reagents): рН = 11.3–11.6; residual hardness — less than 1.0 meq/l; heavy metals precipitation degree — 93–98,9%;
– ultrafiltration: transmembrane pressure – 0.6 bar, partition coefficient — 85%; filtration rate — 375 l/m2h; filtrate turbidity — 0,6 NTU;
– reverse osmosis: concentration of soluble salts using two stage reverse osmosis (in the concentrate) is 2.27 mg/dm³ (48–52 bar at the pressure on the first stage, and 60–64 bar at the pressure on the second stage), total concentration of salts in permeate is 27.4 mg/dm³.

1. Gvozdev V. D., Ksenofontov B. S. Ochistka proizvodstvennykh stochnykh vod i utilizatsiya osadkov (Purification of industrial waste waters and utilization of sediments). Moscow : Khimiya, 1988. 111 p.
2. Frog B. N., Levchenko A. P. Vodopodgotovka : uchebnoe posobie dlya vuzov (Water preparation : tutorial for universities). Moscow : Publishing House of Moscow State University, 1996. 680 p.
3. Tekhnicheskiy spravochnik po obrabotke vody : v dvukh tomakh : perevod s frantsuzskogo (Technical reference book on water processing : in two volumes : translated from French). Saint Petersburg : Novyy Zhurnal, 2007. 1696 p. (in Russian).
4. Kishenevskiy V. P. Tekhnologii podgotovki vody v energetike : spravochnik (Technologies of water preparation in energetics : reference book). Odessa : Feniks, 2008. 400 p.
5. Efimov A. I., Belorukova L. P., Vasilkova I. V., Chechev V. P. Svoystva neorganicheskikh soedineniy : spravochnik (Properties of inorganic compounds : reference book). Under the editorship of V. A. Rabinovich. Leningrad : Khimiya, 1983.