Search

Nitrated lignosulfonates were used to synthesize a water-based magnetic fluid. Lignosulfonates were nitrated by nitric acid under mild conditions and without further purification were used to synthesize a magnetic fluid. Part of the iron(II) were oxidized with an excess of nitric acid, so that the magnetoactive phase under the condensation by action of sodium hydroxide was formed. Optimum conditions for nitration of lignosulfonates and synthesis of a magnetic fluid were experimentally established. The optimum consumption of iron(II) was 1.3–1.5[Formula: see text]g per 1[Formula: see text]g of sodium lignosulfonate. Unlike the initial lignosulfonates, nitrated lignosulfonates have peptizing properties, due to which the precipitate formed during condensation was dispersed to nanoparticles (15–30[Formula: see text]nm). The resulting magnetic fluid had a high magnetic activity and was stable for a long time.

The synthesis of stable silver-containing aqueous solution with magnetoactive particles (26–90 nm) based on the redox reaction of Fe ii cations with diammine silver( i ) hydroxide in the presence of lignosulfonate and tetraethylammonium hydroxide has been developed.

Chromium and its compounds are widely used in various industries. Wastewater from industrial enterprises using chromium compounds are subject to complete disposal at treatment facilities. The possibility of synthesizing a magnetoactive compound by oxidizing part of Fe(II) cations with chromate-anions in the presence of lignosulfonates was investigated. The magnetic activity was measured on Gouy balance, magnetic characteristics were determined by the magnetic granulometry method. It has been shown that the interaction of Fe(II) cations with chromate-anions passes with the formation of an water soluble intermediate without redox transformations at pH 3.4. Using method of the isomolar series, it was determined that the ratio of chromate-ions and Fe(II) cations in the intermediate is 1:2.33. The intermediate solution is stable for a long time. Synthesized magnetoactive compound samples are ferrimagnets. The use of lignosulfonate and the synthesis with heating can achieve a higher magnetic activity of magnetoactive compound. The optimal lignosulfonate consumption is 0.7 g/g Fe.