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Nowadays, the processing of bio-renewable raw materials into biofuels and valuable products, namely, bifunctional carbonyl/carboxyl compounds that serve as the basis for biopolymers, has become one of the most important...

At present, arsenic content in copper concentrates is increasing, which leads to an increase in its content in all smelting products, the largest amount of arsenic is transferred in fine dust (dust composition,%: 10-12 Zn, 11-13 Pb, 8-15 Cu , 12-14 Fe, 5-10 As). Autoclaved leaching of dusts (temperature 160-200 °C, oxygen pressure 0.4-0.8 MPa, molar ratio H2SO4 /(Cu + Zn) = 0.75-2.25) to obtain a copper-zinc solution and a cake containing arsenic, iron and lead was studied. Copper extraction in the solution reaches 92%, zinc 95%. Lead, arsenic and iron are concentrated in the cake. Lead from cake is extracted by leaching in sodium chloride solution (temperature 60-70 ° C, NaCl concentration 300 g / dm3). The extraction of lead into the solution is 95%, subsequently lead is precipitated as lead carbonate.

Mine water from non-ferrous metal deposits is often contaminated with nickel and manganese ions. The entry of these ions, especially nickel, into surface waters and underground aquifers is undesirable since it has a negative effect on living organisms and worsens the condition of drinking water sources. One of the promising methods for selectively extracting nickel ions and obtaining an eluate suitable for further use is sorption by weakly acid cation exchangers with chelate groups of iminodiacetic acid. As part of the study, sorption isotherms of nickel and manganese ions by Lewatit MonoPlus TP 207 cation exchanger in mono- and bicomponent systems were obtained. In monocomponent systems, the maximum static exchange capacity (SEC) of the cation exchanger for nickel ions is 952 mmol/dm3, and in bicomponent systems – 741 mmol/dm3; for manganese ions– 71 mmol/dm3 and 49 mmol/dm3, respectively. It is obvious that the studied cation exchanger has a greater capacity for nickel ions than for manganese ions. The influence of a temperature increase from 300 to 330 K on the sorption of nickel and manganese ions was established: in monocomponent systems, the maximum degree of extraction of the former increases from 65 to 77 % (SEC from 337 to 399 mmol/dm3), and the latter from 21 to 35 % (SEC – from 140 to 229 mmol/dm3); in bicomponent systems, the extraction of nickel ions increases from 59 to 78 % (SEC – from 307 to 429 mmol/dm3), and manganese ions decreases from 20 to 17 % (SEC – from 164 to 131 mmol/dm3). The predominant increase in the indicators is due to the filling of the sorption centers of the ion-exchange resins, which are energetically unfavorable for the exchange of counterions at a lower temperature. The influence of the pH of the solution on sorption was determined: the intensification of the process for nickel ions is observed in the pH range of 8.0-8.5 in a monocomponent solution and 8.0-9.0 in a bicomponent solution, for manganese ions in the range of 8.0-9.5 in both cases. The increase in the degree of extraction of ions and the exchange capacity of the ion exchanger with increasing pH is associated with the appearance of singly charged hydroxocations, dissociation of the functional groups of the sorbent and, to some extent, with the subsequent formation of insoluble forms of nickel and manganese. However, with increasing pH, a decrease in the selectivity of nickel extraction is observed: the ion separation coefficient decreases from 14.0 to 6.0 in the pH range of 6.0-11.0.

The importance of the research is due to the lack of potable water (~1.6 million m3 per year) in a rapidly developing city in the Urals. One way to solve this problem is to purify water from the spent copper mine with a debit of ~4.4 million m3 of water per year. The most advanced techniques recently used for obtaining drinking water of a high quality are based on ion exchange and reverse osmosis, which can ensure an obtainment of water with initial contents of impurities much below the maximum permissible values. Based on the real experience the article compares sorption and membrane technologies in terms of water purification efficiency and cost of potable water production. The large-scale tests of mine water purification were carried out at sorption and reverse osmosis pilot plants with the capacity of 1 m3 per hour for the incoming flow. The source water had the following composition, mg/dm3: 0.5–0.9 Mn; 1.0–1.7 Ni; 80-140 Ca; 30-40 Na; 40-70 Mg; 0.2–0.6 Cu; 8.1–9.5 Si; 0.01–0.03 Zn; 0.01–1.70 Fe; <0.01 Al; < 0.005 As; < 0.005 Pb. At the same time the salinity was 640–680 mg/dm3, the water hardness was 9.5–11.5 mmol/dm3 and pH was 7.0-7.5. The content of non-mentioned impurities was below the detection limit. The resulting treated water met the requirements for the quality of potable water for both purification techniques. It was concluded, that the best option for treatment of mine water is ion exchange.