SU679636A1 - Method of controlling the process of purifying nickel-cobalt solutions from iron - Google Patents

Description

The invention relates to hydrometry of non-ferrous metals and can be used in particular when cleaning solutions from iron in cobalt and nickel production processes. A known method for controlling the purification process of nickel-cobalt solutions from iron by oxidation and precipitation consists in regulating the redox potential of the medium by changing the oxidant consumption and pH values by changing the consumption of the neutralizer 1. According to a known method, the magnitude of the redox potential is kept within 540-620 mV relative to the normal silver chloride electrode. However, maintaining the redox potential in this range, even with a stable value of the medium environment, leads to inevitable coprecipitation of nickel and cobalt from solutions in which the concentration of the latter is higher than iron. This leads to additional consumption of reagents for subsequent extraction of cobalt and nickel from the resulting precipitates. an increase in precipitation stages requires additional reaction equipment for the off-set process. Y) the method is different from the known one in that the magnitude of the redox potential is maintained at a minimum value of 180-280 mV relative to the silver-chloride electrode, depending on the salt composition of the nickel-cobalt solution. This makes it possible to selectively precipitate iron and reduce reagent consumption. FIG. 1 p |) the process flow diagram with a control and regulation system is given, the regisue process, the proposed method in FIG. 2 curves of changes in the concentration of iron and cobalt, as well as the values of the redox potential (ORP) and the pH of the medium over time for the periodic iron cleaning process; in fig. 3 - curves of changes in the values of the redox potential over time for the periodic process of cleaning solutions with different salt from iron (1,2,3 -number of experiments)

in fig. 4 curves of changes in the concentration of iron and cobalt, as well as the values of the redox potential of the medium over time for a periodic process of purification from iron while maintaining the ORP at an extreme value.

The process flow diagram shows a collection 1 of the initial solution, a reactor 2, pumps 3 and 4 / circuits 5–9 for stabilizing the technological parameters of the cleaning process (solution consumption for the pH / ORP / temperature cleaning process and slurry level in the reactor); contour 10 level controls in the collection of the initial solution.

 : -h: 1:., h; 1; s solutions of aa. pump i С., ;;, -; to: ori with a volume of 9 heated: 1:; / ;;,;.: l Peer Upon reaching it is required; . : iM- riepaTypbi measure k1g volume-growth ::; hh-- r1:; bNG1uT TOTAL PROBE,

.; i-V,.; i /; i; y: r values of pЯ and oxidant ;; .: -: / 1 by the way Qlnoj: o vir.captial and; s i.H ;; -: .. ppossass ochr; weave. JlByxBa

..-.:, .. aiejfeso oKK iJUiQT

;;: -: ate ai -: -: .., ..: -: tic. the three-row &ch; siege: .ley:.:. i: BiiJ, c ocHO: i i :.

.. H ;; i ;; ; (;; pOl: lHifOK сОЛК-й Ч i; IО1лес:; for sting

 through;.,.; -, IVWel; ,:, school. l:: i, yrOT znakl; -m-g. pH ORP, ai-l;

J-1 containing {ll-: 1 :: both. 17Ь |; -l and F - ne: ;; -; ipae / lix IjvHjoax ,, After the occlusion of vocaa Clean; - -th is the walkie-talkie ..V y.i.ny Havjpaii.ifinpv 5 .g. hev1; 4e .yurl l. .-tptsruscht her: ;; fi, P1 /; rat; | c; (;

. -plaiera (total content of ifoO -: 11: LoraoGyor1-1 Msi ch5):.

1 :: 1; LADOVAPI L AND V .1

-; t. what i-i. "Won; -; .-: L in solution, i - ;; eh) cuo-.i; R3cc;

extremal: -: -, (MHiiKf / iEUibKosi:, -: jt,.: vanHio oxides --- /;,;.:: iososos; stepia) L; Tc,.: s: -; СГо potential; AFP average;; .-, B beginning orib - T-

-fc-;); e.; 1YU-VOS -ijbi x; yrakterizuel about - stagging

ncial system / Fe. and the fall-t; / mena: the concentration of two: et: -1oGo of iron in solution. After the growth of the redox potential is caused by an excess: the concentration of the oxidizer is undesirable, since it leads to the coexistence of the same.

The nature of the potential change curve, as well as the position of the extremum and its value depend on the initial conditions of the experiments - salt composition / v r-gut, reagent feed rates, etc., however, the extreme (minimum) value of each redox curve potential corresponds to almost complete iron deposition

According to the value of the redox potential at the extreme (minimum) value in the process of iron-oxide it provides the maximum depth of solution cleaning from iron (slz.tsy). Cobalt sedimentation at shishmalnom. meaning

the redox potential is terminated.

Example. The process of iron cleaning is carried out in the reactor 2. The initial solution containing 0.62 g / l of iron, 88 g / l of coal, 8g / l of nickel and 3.5 g / l of copper, is continuously fed from collection 1 reactor. This also continuously receives air and soda solution.

The solution flow rate is kept stable, the soda flow rate is automatically changed to maintain the pH of the reaction medium in the range of 3-5 pH. The airborne oxidizer solution is automatically changed so that the magnitude of the redox potential for these specific conditions (salt composition, pH, temperature) is maintained at the minimum value. In the reactor 2, the pulp level and temperature are also automatically maintained.

In the reactor, iron is oxidized to trivalent and precipitated as a result of hydrolysis in the form of basic sulfates. The resulting slurry is continuously pumped for filtration.

Tests of the proposed method for controlling the purification process of nickel-cobalt solutions from iron show that the co-precipitation of cobalt decreases by 30-35% compared with the control method with a stable ORP value, while ensuring that iron is almost completely released from the solution in the sediment. Accordingly, reagent consumption is reduced. The redistribution capacity is increased by improving the filterability of the sediment.

The method is rather simply implemented using general industrial means and methods of automatic control and regulation, widely used in existing systems for automating hydrometallurgical processes.

Claims (1)

1. Authorship certificate of the USSR No. 434117, cl. From 22 to 23/04, 1972. - On futbmfanufO  Riga.1 2i SO to Iff Lying to him oap.nv and w in IG t by UpfMH, him. Th / y