Method of renovating and afforesting slag mountain with humic acid substance

Abstract

A method utilizing a humic acid substance for renovating and afforsesting slag is provided. A humic acid substance may be utilized for passivation, adsorption, reduction, chelation and immobilization of harmful heavy metal elements in slag, for example, Cr, As, Cd, Ni, Pb, Ba, Hg, Co, Se, Ag and Be, and aggregating the slag, thereby detoxifying the slag and producing artificial earth. The artificial earth may be used in combination with a carrier bacterial fertilizer to continuously produce the active humic acid substance, achieving an effect similar to the combination of blood transfusion and blood production, thereby forming a high-quality artificial soil.

Claims

1. A method of renovating and afforesting a slag mountain with a humic acid substance, the method comprising: 1) preparing an artificial earth having a particle diameter less than 0.5 mm by pulverizing slag from the slag mountain and adding 0.1-5 wt. %, with respect to the slag, of the humic acid substance to the slag during pulverizing; 2) preparing an artificial soil by adding a carrier bacterial fertilizer into the artificial earth according to a mixing ratio of 1:20-300 by weight of the carrier bacterial fertilizer to the artificial earth, wherein the carrier bacterial fertilizer is semi-coke bacterial fertilizer or slag bacterial fertilizer; 3) covering the surface of the slag mountain with the artificial earth to form an artificial earth layer with a thickness of 100-2,000 mm and compacting the artificial earth layer, and then covering the artificial earth layer with the artificial soil to form an artificial soil layer having a thickness of 100-300 mm; and 4) subsequently afforesting the slag mountain.

2. The method of renovating and afforesting a slag mountain with a humic acid substance according to claim 1, wherein the humic acid substance is one or more selected from the group consisting of humic acid, potassium humate, sodium humate, and biomass pyrolysis oil.

3. The method of renovating and afforesting a slag mountain with a humic acid substance according to claim 1, wherein the slag is pulverized with a pulverizer, the pulverizer is one selected from the group consisting of a ball mill, a cone crusher a baffle crusher, an impact crusher, a hammer crusher, a rotary crusher, a composite crusher, a hydraulic crusher, a deep cavity crusher, a roll crusher, a and a jaw crusher.

4. The method of renovating and afforesting a slag mountain with a humic acid substance according to claim 3, wherein the cone crusher is selected from the group consisting of a Symons cone crusher and a hydraulic cone crusher.

5. The method of renovating and afforesting a slag mountain with a humic acid substance according to claim 3, wherein the roll crusher is a toothed roller crusher.

6. The method of renovating and afforesting a slag mountain with a humic acid substance according to claim 1, wherein the semi-coke bacterial fertilizer or the slag fertilizer is obtained by uniformly loading a microbial bacterial fertilizer on a biological semi-coke powder or a gasifier slag to a level of 3-20% by weight of the microbial bacterial fertilizer with respect to the biological semi-coke powder or the gasifier slag, and drying; wherein the microbial bacterial fertilizer comprises microbial thallus or an active enzyme.

7. The method of renovating and afforesting a slag mountain with a humic acid substance according to claim 6, wherein the microbial thallus is from at least one selected from the group consisting of Bacillus, Saccharomyces cerevisiae, Aspergillus oryzae, Rhizobium, Azotobacteria and Phosphorus bacteria.

8. The method of renovating and afforesting a slag mountain with a humic acid substance according to claim 6, wherein the active enzyme is one or more enzyme selected from the group consisting of a protease and a plant kinase.

9. The method of renovating and afforesting a slag mountain with a humic acid substance according to claim 6, wherein the loading comprises: mixing microbial bacterial fertilizer solution and the biological semi-coke powder or the gasifier slag uniformly, to allow the microbial bacterial fertilizer loading on the biological semi-coke powder or the gasifier slag.

10. The method of renovating and afforesting a slag mountain with a humic acid substance according to claim 6, wherein the biological semi-coke powder has a particle diameter of 0.01-5 mm and is obtained by rapidly pyrolyzing agricultural and forest residues to prepare biological semi-coke, then pulverizing the biological semi-coke into the biological semi-coke powder.

11. The method of renovating and afforesting a slag mountain with a humic acid substance according to claim 10, wherein the rapidly pyrolyzing comprises: pyrolyzing the agricultural and forest residues in reaction conditions of absence of air at 490-600 C. for 0.1-20 s.

12. The method of renovating and afforesting a slag mountain with a humic acid substance according to claim 6, wherein the gasifier slag is a product formed by chilling a cinder generated when gasifying pulverized coal in an airflow bed at a temperature of 1,300 C. or more.

13. The method of renovating and afforesting a slag mountain with a humic acid substance according to claim 6, wherein prior to uniformly loading the microbial bacterial fertilizer on the biological semi-coke powder or the gasifier slag, the method further comprising: uniformly mixing 0.1-2 parts by weight of humectant with 100 parts by weight of the biological semi-coke powder or the gasifier slag, so as to prepare an modified biological semi-coke powder or an modified gasifier slag; wherein the humectant is selected from the group consisting of an anionic surfactant, a nonionic surfactant, a silanol nonionic surfactant, and a solvent which has a small surface tension and is miscible with water.

14. The method of renovating and afforesting a slag mountain with a humic acid substance according to claim 13, wherein the solvent is one or more selected from the group consisting of ethanol, propylene glycol, glycerin and dimethyl sulfoxide.

Description

DETAILED DESCRIPTION OF THE EMBODIMENTS

(1) The features of invention will be described in detail with reference to the examples.

(2) The semi-coke bacterial fertilizer is obtained by preparing the silanol nonionic surfactant GSK-588 corresponding to 0.5 wt. % of the biological semi-coke powder into the 2 wt. % aqueous solution, mixing the aqueous solution with the biological semi-coke powder uniformly so as to prepare a modified biological semi-coke powder, then the microbial bacterial fertilizer is uniformly loaded on the modified biological semi-coke powder, and performing a low-temperature drying under a temperature less than 45 C.; wherein the microbial bacterial fertilizer is a microbial bacterial fertilizer solution containing Bacillus, Rhizobium, Azotobacteria and Phosphorus bacteria corresponding to 10 wt. % of the biological semi-coke powder. The biomass pyrolysis oil and biological semi-coke are obtained by pyrolysis reaction of corn stalk in a condition of absence of air and a temperature of 550 C. for 10 seconds, wherein the biological semi-coke is pulverized into the powder having a particle size of 0.01-5 mm to prepare the biological semi-coke powder, which is used for preparing the semi-coke bacterial fertilizer.

(3) The slag bacterial fertilizer is obtained by preparing the silanol nonionic surfactant GSK-588 corresponding to 0.5 wt. % of the gasifier slag into the 2 wt. % aqueous solution, mixing the aqueous solution with the gasifier slag uniformly, then the microbial bacterial fertilizer is uniformly loaded on the gasifier slag, and performing a low-temperature drying under a temperature less than 45 C.; wherein the microbial bacterial fertilizer is a microbial bacterial fertilizer solution containing Bacillus, Rhizobium, Azotobacteria and Phosphorus bacteria corresponding to 10 wt. % of the biological semi-coke powder.

Example 1

(4) In the first step, while the slag is added into the cone crusher for pulverization, 3 wt. % of sodium humate corresponding to the slag and a small amount of water are added, then pulverizing to obtain artificial earth particles having a particle diameter less than 0.5 mm. In addition, while the slag is pulverized, the mixing of the pulverized slag and the sodium humate is intensified so as to form a water-stable granular structure having a particle diameter more than 0.25 mm.

(5) In the second step, the semi-coke bacterial fertilizer and the above-mentioned artificial earth particles are uniformly mixed based on a weight ratio of 1:150, so as to prepare high-quality artificial soil.

(6) In the third step, initially covering the surface of the slag mountain with a layer of artificial earth particles with a thickness of 600 mm, and compacting the artificial earth particles layer to insulate air and prevent spontaneous combustion; then covering a layer of high quality artificial soil with a thickness of 150 mm, Table 1 shows the content of heavy metals measured according to the method stipulated in GB15618-1995 Soil Environmental Quality Standard. The soil is then planted with flowers, grass and trees, the plants are elaborately maintained to form a green cover.

Example 2

(7) In the first step, while the slag is added into the cone crusher for pulverization, 0.1 wt. % of potassium humate corresponding to the slag and a small amount of water are added, then pulverizing to obtain artificial earth particles having a particle diameter less than 0.5 mm. In addition, while the slag is pulverized, the mixing of the pulverized slag and the potassium humate is intensified so as to form a water-stable granular structure having a particle diameter more than 0.25 mm.

(8) In the second step, the slag bacterial fertilizer and the above-mentioned artificial earth particles are uniformly mixed based on a weight ratio of 1:300, so as to prepare high-quality artificial soil.

(9) In the third step, initially covering the surface of the slag mountain with a layer of artificial earth particles with a thickness of 2,000 mm, and compacting the artificial earth particles layer to insulate air and prevent spontaneous combustion; then covering a layer of high quality artificial soil with a thickness of 100 mm, Table 1 shows the content of heavy metals measured according to the method stipulated in GB15618-1995 Soil Environmental Quality Standard. The soil is then planted with flowers, grass and trees, the plants are elaborately maintained to form a green cover.

Example 3

(10) In the first step, while the slag is added into the cone crusher for pulverization, 5 wt. % of sodium humate corresponding to the slag and a small amount of water are added, then pulverizing to obtain artificial earth particles having a particle diameter less than 0.5 mm. In addition, while the slag is pulverized, the mixing of the pulverized slag and the sodium humate is intensified so as to form a water-stable granular structure having a particle diameter more than 0.25 mm.

(11) In the second step, the semi-coke bacterial fertilizer and the above-mentioned artificial earth particles are uniformly mixed based on a weight ratio of 1:100, so as to prepare high-quality artificial soil.

(12) In the third step, initially covering the surface of the slag mountain with a layer of artificial earth particles with a thickness of 100 mm, and compacting the artificial earth particles layer to insulate air and prevent spontaneous combustion; then covering a layer of high quality artificial soil with a thickness of 200 mm, Table 1 shows the content of heavy metals measured according to the method stipulated in GB15618-1995 Soil Environmental Quality Standard. The soil is then planted with flowers, grass and trees, the plants are elaborately maintained to form a green cover.

Comparative Example 1

(13) The renovation and afforestation of slag mountain are performed with humic acid substance according to the method in Example 1, the difference resides in that sodium humate is not added in the first step.

(14) Table 1 shows the content of heavy metals measured according to the method stipulated in GB15618-1995 Soil Environmental Quality Standard.

Comparative Example 2

(15) The renovation and afforestation of slag mountain are performed with humic acid substance according to the method in Example 1, the difference resides in that the semi-coke bacterial fertilizer is not added in the second step.

(16) Table 1 shows the content of heavy metals measured according to the method stipulated in GB15618-1995 Soil Environmental Quality Standard.

Comparative Example 3

(17) The renovation and afforestation of slag mountain are performed with humic acid substance according to the method in Example 1, the difference resides in that the semi-coke bacterial fertilizer is added in the first step along with the sodium humate.

(18) Table 1 shows the content of heavy metals measured according to the method stipulated in GB15618-1995 Soil Environmental Quality Standard.

Comparative Example 4

(19) The renovation and afforestation of slag mountain are performed with humic acid substance according to the method in Example 1, the difference resides in that the semi-coke bacterial fertilizer and the above-mentioned artificial earth particles are uniformly mixed based a weight ratio of 1:10.

(20) Table 1 shows the content of heavy metals measured according to the method stipulated in GB15618-1995 Soil Environmental Quality Standard.

Comparative Example 5

(21) The renovation and afforestation of slag mountain are performed with humic acid substance according to the method in Example 1, the difference resides in that the semi-coke bacterial fertilizer and the above-mentioned artificial earth particles are uniformly mixed based a weight ratio of 1:400.

(22) Table 1 shows the content of heavy metals measured according to the method stipulated in GB15618-1995 Soil Environmental Quality Standard.

(23) TABLE-US-00001 TABLE 1 Examples Comparative Examples Heavy metals 1 2 3 1 2 3 4 5 Fe mg/Kg 10 5 8 300 100 20 24 10 Cd mg/Kg ND ND ND 5 3 ND ND ND Cr.sup.+6 mg/Kg ND ND ND 4 2 ND ND ND Pb mg/Kg ND ND ND 50 20 ND ND ND Hg mg/Kg ND ND ND 1 ND ND ND ND As mg/Kg ND ND ND 20 ND ND ND ND Note: ND = not detected