Method of preparation and application of ion-keeper adsorbent

Abstract

The invention belongs to the field of chemical separation, hydrometallurgy and resource recovery and provides a method for preparing and applying of ion-keeper adsorbent. By adjusting the pH to selective oxidation to achieve the oxidation of ferrous iron into ferric iron. Separates the iron after the hydrothermal reaction; By using of ion imprint “ion keeper” effect and biomass as raw materials, to prepare the adsorbent with internal rules, hierarchical pores and high selectivity. It can be used for deep purification of chromium solution, such as iron, aluminum, vanadium and other impurities in the solution; After the deep purification of chromium solution, then adjusting the pH, adding appropriate hydrating agent, by hydrothermal precipitation treatment of chrome, filtration, acid washing and calcination to obtain chromium oxide crystal. It achieves the purification of chromium, iron, aluminum and chromium. The recycling and comprehensive utilization of waste resources are also realized. The process is simple, the iron, aluminum, vanadium and other impurities are in the selective adsorption. Chromium solution after deep purification can be processed for high purity chromium products to provide technical support.

Claims

1. A preparation method of ion-keeper adsorbent, comprising: (1) providing a chromate solution having a concentration of 0.1˜1.5 mol/L, wherein the pH of the chromate solution is adjusted to 2˜6; (2) washing, breaking and soaking a biomass in the chromate solution for 2˜36 h to obtain a mixture of biomass chromate; a mass ratio of mass the biomass to the chromate solution is 1: 2˜8; (3) transferring the biomass chromate mixture obtained in step (2) into a reaction kettle and aged-aging for 2˜8 hours at a temperature of 120 to 220° C. to obtain a chromium-keeper adsorbent, which is ion-keeper adsorbent.

2. The preparation method claim 1, wherein the biomass is one or more of a kelp, a straw, a sawdust, a leaf or a peel.

3. An application method of the ion-keeper obtained in the preparation method of claim 1, comprising: (1) dissolving a chromium-containing solid or chromium-containing solution in an acid solution, and a pH is adjusted to 0.5˜4.5, an insoluble material is filtered to obtain a chromium liquid 1; pickling the insoluble material obtained by filtration until the chromium content in line with the national environmental protection standard; (2) a pH of the chromium liquid 1 obtained in the step (1) is adjusted to 0.5˜6.0, adding a reducing agent, and the pH is adjusted to 1.0˜5.0, obtaining a separated ferrochrome qualified liquid; adding oxidant to obtain a mixed solution of trivalent iron, trivalent chromium and trivalent aluminum; the mixed solution is subjected to hydrothermal reaction, and the reaction is accompanied by constant stirring; after the reaction is finished, a filtrate and Fe-containing sediment are obtained; the pH of filtrate is adjusted to 0.5 to 3.5 and a chrome storage solution is gotten, that is chromium liquid 2; hydrothermal conditions are in the range of 50˜150° C. and 0.5Mpa˜2.5 Mpa for 0.5˜10 hours; (3) adding the ion keeper adsorbent to the chromium liquid 2 obtained in the step (2) or passing the chromium liquid 2 through a fixed bed equipped with the ion-keeper adsorbent; a ratio of the ion-keeper adsorbent and the chromium liquid 2 is 1:150˜500 and then shock or stirring 5˜24 hours, get sinking a chrome qualified liquid 3; (4) high temperature hydrothermal: the chrome qualified liquid 3 and hydrating agent is placed in a closed reactor hydrothermal reaction, heated to 150˜400° C,the pressure of 0.5 Mpa˜4.5 Mpa, insulation 1 to 5 hours; a reaction product is filtered, washed with acidic liquid and dried to obtain green filter cake which is high purity chromium compound, calcined at 500˜1200° C. and transformed into nano-chromium oxide solid.

4. The preparation method of claim 3, wherein the reducing agent is methanol, ethanol and straw or two of the above mixture.

5. The preparation method of claim 3, wherein an oxidizing agent is selected from the group consisting of oxygen, air, hydrogen peroxide, ozone or sulfuric acid radicals.

6. The preparation method of claim 4, wherein an oxidizing agent is selected from the group consisting of oxygen, air, hydrogen peroxide, ozone or sulfuric acid radicals.

7. The preparation method of claim 3, wherein the hydrating agent is selected from oxalic acid, cellulose, methanol, formaldehyde, formic acid, ethanol or glucose.

Description

DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 400-fold photomicrograph of the chromium-controlled adsorbent prepared in accordance with the present invention.

(2) FIG. 2 Cross-sectional view of the microparticle of the adsorbent prepared by the present invention.

(3) FIG. 3 The infrared spectrum of the chrome-controlled adsorbent.

(4) FIG. 4 The chromatogram of chromium oxide obtained by calcination of the chromium-containing compound.

(5) FIG. 5 The TEM of the chromium oxide obtained by calcination of the chromium-containing compound.

(6) FIG. 6 The HRTEM of the chromium oxide obtained after calcination of the chromium-containing compound.

(7) FIG. 7 The XRD patterns of chromium oxide obtained after calcination of the chromium-containing compound.

DETAILED DESCRIPTION

(8) Specific embodiments of the present invention are described in further detail with reference to the technical solutions and the accompanying drawings, but the invention is not limited to the specific embodiments.

Implementation Example 1

(9) High carbon ferrochrome as raw material, and the ingredients are as follows:

(10) TABLE-US-00001 TABLE 1 high carbon ferrochromium composition Ingredients Fe and Cr C Si P S others Content 42~47 6~10 3~4 0.03~0.04 0.02~0.05 38~41

(11) 15.0 g of high carbon ferrochrome was dissolved in 35 ml volume fraction of 60% sulfuric acid solution, then water bath heated to 80° C., constant temperature 30 min to fully respond. And then it was cooled to room temperature, a small amount of insoluble matter was filtered to obtain a mixed solution filtrate 1 containing chromium, iron and other impurities, diluted 10 times, and adjusted to pH 2.8 with sulfuric acid at a mass fraction of 5%. In the filtrate 1 by adding 0.5 ml of methanol, it was hydrothermaled at 160° C. reduction 4 h to turn all the hexavalent chromium into trivalent chromium, then filtration. 10 ml of this filtrate was taken and added 2 ml of hydrogen peroxide with 20% mass fraction, stirred for 30 min, then placed in 18 ml auticlave, incubated at 90° C. for 2 hours, cooled to room temperature and filtered to get Fe sediment and green chromium filtrate 2.

(12) Some washed and dried kelp was broken into about 5 cm.sup.2 pieces with scissors. 50 g kelp pieces was weighed and immersed in 150 ml 0.4 mol/L potassium chromate solution, placed in 80° C. oven for 8 hours. The mixture was transferred to an autoclave and aged at 210° C. for 5 hours. After completion of the reaction, the resulting solid adsorbent sample was washed with hydrochloric acid, filtered, washed with deionized water and dried at 80° C. for 24 hours (the adsorbent was shown in FIG. 1 to 3).

(13) The concentration of chromium (VI) and iron (III) in the mixture was 120.95 mg/L and 16.91 mg/L, respectively, then adding 1 g of adsorbent to 500 ml of chromium filtrate 2. After stirring for 2 hours, the adsorbent was separated by filtration, and the content of iron (III) in the solution was detected. Then, 1 g of adsorbent was added to the solution, and the mixture was stirred for 12 hours. The purified chromium liquid 3 was obtained. Iron (III) concentration, the results are as follows:

(14) TABLE-US-00002 Inicial After 18 h After 24 h concentration concentration concentration Removal rate (mg/L) (mg/L) (mg/L) (%) Cr 120.95 — — — Fe 16.91 0.175 0.042 99.75

(15) 15 ml of chromium solution 3 was taken and added 1.5 ml of methanol, with the mass fraction of 5% sulfuric acid to adjust the pH to 2.1, placed in a 18 ml autoclave, heated at 210° C. for 1.5 hours, cooled to the room temperature, washed with water, dried at 120° C. for 2 hours and calcined at 600° C. for 3.5 hours to obtain green chromium oxide crystals (product shown in FIGS. 4 to 7).

Implementation Example 2

(16) The chromium aluminum slag as the raw material.

(17) TABLE-US-00003 TABLE 2 The ingredients of chromium aluminum slag Ingredient Cr Al Si P S Others Content 62~67 18~25 3~4 0.03~0.04 0.02~0.05 3~5

(18) 100.0 g chrome aluminum slag was taken and dissolved in 300 ml volume fraction 13% sulfuric acid solution, heated for 35 min to make chrome aluminum slag reaction completely. The material after the reaction was filtered to obtain a chromium-aluminum mixed solution. 200 ml of filtrate 1 was taken and added 1.0 ml of methanol, then hydrothermaled reduction in 160° C. for 4 hours to turn all the hexavalent chromium into trivalent chromium, filtered to get chrome aluminum mixture 2.

(19) The orange peel was washed and crushed into about 1 cm2 pieces. 30 g of orange peel was weighed and immersed in potassium chromate solution in a 50° C. oven for 2 hours. After completion of the reaction, the obtained chromium-resistant adsorbent sample was washed with hydrochloric acid, washed with deionized water and dried at 80° C. for 24 hours.

(20) 2 g of chrome-resistant adsorbent was added to 100 ml, pH 3.05 chrome-aluminum mixture 2, shaken in the shaker for 26 hours. The mixture was centrifuged and the supernatant was taken for measuring aluminum contents. The results are as follows:

(21) TABLE-US-00004 Initial After 18 h concentration concentration Removal rate (mg/L) (mg/L) (%) Cr 105.20 — — Al 6.17 0.037 99.40

(22) 20 ml supernatant was taken and added 1.0 ml of ethanol, adjusted the pH to 1.9, and added to a 18 ml of closed reactor, heated in 140° C. for 2 hours and calcined at 450° C. for 2.5 hours to obtain chromium oxide crystals.

(23) The filtrate and the washing solution were adjusted to pH 8 to obtain a white precipitate, filtered, washed with deionized water, dried and calcined at 300° C. for 2.5 hours to obtain an alumina solid. The filtrate and the washing liquid were repeated during the above process.

Implementation Example 3

(24) The chrome ore as the starting material

(25) TABLE-US-00005 TABLE 3 Chromium Ingredients Ingredients Cr Fe Al Mg Ca Others Content 18~26 15~24 9~13 8~12 3~5 14~16

(26) 15.0 g chrome ore was dissolved in 50 ml volume fraction of 45% sulfuric acid solution, then water bath heated in 80° C., constant the temperature for 30 min to make sure the chrome ore was fully reacted. And then cooled to room temperature, a small amount of insoluble matter was filtered to obtain a mixed filtrate containing chromium, iron and other impurities. The mixture was diluted to 10 times and adjusted the pH to 2.5 with sulfuric acid at a mass fraction of 5%. 0.5 ml of methanol was added to the filtrate 1 to hydrothermal 160° C. reduction for 4 hours to turn all the hexavalent chromium into trivalent chromium, containing trivalent chromium solution. 2 ml of hydrogen peroxide with 20% mass fraction was added to 10 ml of the above trivalent chromium solution and stirred for 30 min, then placed in a 18 ml autoclave, incubated at 90° C. for 2 hours, cooled to room temperature and filtered to obtain Fe-containing sediment and green chromium filtrate 2.

(27) 10 g of crushed pineapple skin was soaked in 50 ml 0.25 mol/L sodium chromate solution, placed in 60° C. oven for 2 hours. The mixture was transferred to an autoclave and aged at 150° C. for 3 hours. After completion of the reaction, the obtained solid chromium-resistant adsorbent sample was pickled, filtered, and dried at 80° C. for 24 hours. 1 g of the chrome-controlled adsorbent was added 20 ml of the filtrate 2 to be deeply purified, and then mixed for 12 hours after stirring to obtain the chromium filtrate 3.12 ml of filtrate 3 was added 0.2 ml of methanol, adjusted the pH to 2.15, and then added to a 25 ml closed reactor, heated in 160° C. for 4 hours. After completion of the reaction, the mixture was cooled to room temperature and filtered. The resulting solid was dried at 120° C. for 4 hours and calcined at 500° C. for 2.5 hours to obtain nano-chromium oxide.

Implementation Example 4

(28) The straw was washed, dried and broken into pieces with scissors. 50 g of straw was weighed and immersed in 100 ml of 0.3 mol/L potassium chromate solution and immersed in a 50° C. oven for 2 hours. The mixture was transferred to an autoclave and aged at 180° C. for 2 hours. After completion of the reaction, the obtained solid sample was pickled, filtered, and dried at 80° C. for 24 hours.

(29) The concentration of vanadium (V) and chromium (VI) in the mixed solution was 9.803 mg/L and 88.79 mg/L, respectively, in the mixture of 0.5 g adsorbent and 150 ml and pH value of 8.15. Vanadium and chromium (V) and chromium (VI) in the solution were analyzed. The adsorption capacity of adsorbent to vanadium (V) and chromium (VI) was calculated. The results were as follows:

(30) TABLE-US-00006 Initial Concentration Adsorption Removal Initial Cr/V 4 h after Cr/V concentration after 4 h capacity rate concentration concentration (mg/L) (mg/L) (mg/g) (%) ratio ratio V 9.803 0.035 2.93 99.64 9:1 2549:1 Cr 88.79 89.23 — —

(31) 5.0 ml of methanol was added to 300 ml supernatant, the pH was adjusted to 2.30, and the mixture was added to a 500 ml closed reactor, heated in 150° C. for 3.5 hours. After completion of the reaction, the mixture was cooled to room temperature and filtered. The resulting solid was dried at 110° C. for 2 hours and calcined at 500° C. for 2.5 hours to obtain chromium oxide crystals.