AU2020101916A4 - Reclamation method of abandoned coal storage yard - Google Patents

Abstract

The present invention relates to a method for reclamation of abandoned coal storage yard, in which the topsoil of the proposed reclaimed coal storage field is stripped, mixed with straw and decomposed organic fertilizer, and uniformly mixed to obtain ridge soil. Using ridge soil to pile up a ridge band on the subsoil exposed after stripping the surface soil from the coal storage yard. After spraying compound microbial inoculum on the ridge band, the ridge can be covered with black plastic film with air permeability, then open the plastic film next year, and plant crops on the ridges. In that reclamation method, the decomposition and transformation of the coal powder in the surface soil can be accelerated, the soil nutrient can be activate, the status and permeability of the soil nutrients can be improved, and the reclamation and reasonable utilization of the waste land of a coal storage yard can be realized. It provides an effective solution for the safe and efficient reclamation of abandoned coal storage yard in China.

Description

AUSTRALIA

PATENTS ACT 1990

PATENT SPECIFICATION FOR THE INVENTION ENTITLED:

Reclamation method of abandoned coal storage yard

The invention is described in the following statement:-

Reclamation method of abandoned coal storage yard

TECHNICAL FIELD

[0001] The present invention belongs to the technical field of land reclamation and soil

improvement, and relates to a method for reclamation of an abandoned mineral storage

site. The efficient and safe reclamation method is particularly suitable for a waste site of

long-term pile of coal in that less plateau area.

BACKGROUND

[0002] China is a large coal producer, accounting for more than half of the world's

output. In the process of production, transportation and sales of coal, a large number of

coal storage yards are required for turnover. In recent years, with the changes in the coal

market and the implementation of the capacity of production policy for coal, some

seriously polluted open-air coal storage yards have been gradually abandoned, which not

only occupies a large amount of land, but also pollutes the environment.

[0003] During coal storage in the coal storage yard, due to the long-term

pressure and infiltration of coal on the site, the surface soil is compacted, the

bulk density is increased, and the air permeability and water permeability are

deteriorated. In addition, a large amount of pulverized coal enters the soil,

changing the structure and chemical composition of the soil. After the coal

storage yard is abandoned, it is urgent to solve the above problems in the

process of reclamation.

SUMMARY

[0004] The purpose of the present invention is to provide a method for

reclamation of waste coal yard, so as to improve soil nutrient status and

permeability, and realize reclamation and rational utilization of waste land of

coal yard.

[0005] The waste coal yard reclamation method according to the present

invention is to strip the topsoil of the proposed reclamation coal yard, and add

straw and decomposed organic fertilizer. Homogenize to obtain that ridge soil;

piling the ridge band on the bottom soil expose after stripping the surface soil

of the coal storage yard with the ridge soil, spraying the compound microbial

inoculum onto the ridge bands, and covering the ridges with the black plastic

film with pores; opening the plastic film next year to grow crops on a ridge.

[0006] As a preferred embodiment of the reclamation method of the present

invention, the mixing mass ratio of the stripped topsoil to the straw and the

decomposed organic fertilizer was 100: 0 .25-1 . 1~4.

[0007] Wherein, the straw is corn straw or sorghum straw, and the straw can

be crushed into 1-5cm in length for use.

[0008] Organic fertilizer is one of cow, pig, chicken and sheep dung, or any

mixture of several kinds at any ratio.

[0009] Further, in the reclamation method of this invention, the stripping

thickness of the topsoil is generally 20 to 30 cm.

[0010] In the process of reclamation, the stripped topsoil and the ridge soil

obtained by mixing straw and decomposed organic fertilizer with the stripped surface soil are stacked nearby, and the surface is covered during stacking, so as to prevent the loss of soil nutrients.

[0011] Further, in the present invention, an appropriate amount of urea may

be added to the ridge soil to adjust the carbon/nitrogen ratio of the ridge earth.

The added amount of urea is 3 to 8 kg of urea per 100 tons of bed soil.

[0012] In the reclamation method of the present invention, preferably, the

stacked ridges have a width of 80 to 100 cm, a height of 30 to 40 cm, and a

pitch of 80-120 cm.

[0013] As a preferred embodiment of the reclamation method of the present

invention, the compound microbial inoculum used in the present invention

is a mixed-inoculum composed of Bacillus subtilis, Bacillus megaterium,

Pseudomonas and Penicillin.

[0014] After spraying the compound microbial inoculum onto the ridge, the

surface of the ridge shall be kept at a suitable soil moisture so that the

microbial inoculum can fully react with the soil.

[0015] Preferably, the black mulch film for covering the ridge band of the

present invention is a silver-black two-colour mulching film having a

thickness of 0.015 mm on which a small hole is made every 0.5 m for air

permeability.

[0016] As a preferred embodiment of the reclamation method of the present invention, the

crop planted on the ridge belt is preferably corn.

[0017] According to the present situation of serious pollution and large

occupied land area of the abandoned coal storage yard, the invention proposes

a safe and efficient reclamation method suitable for the waste coal storage

yard after a large number of experimental studies in combination with the soil

characteristics of the waste coal storage yard.

In that reclamation method, the strip surface soil and the organic matter are

mixed and sprayed with the compound microbial inoculum. The film is

covered with the plastic film to maintain proper temperature and water. Under

the action of microbial inoculums, it can accelerate the decomposition and

transformation of coal powder in topsoil, activate soil nutrients, improve soil

nutrient status and permeability, realize the reclamation and rational

utilization of abandoned land in coal storage yard, eliminate the air, soil and

water pollution caused by coal dust, turn the waste land into cultivated land,

and realize the sustainable development goal of resource efficiency and

environment-friendly, which is of great significance to improve the

ecological environment of mining area, increase land resources and realize

the balance of occupation and compensation of cultivated land.

[0018] In the reclamation method of the present invention, the concentrated

surface soil of pulverized coal is stripped and treated in a concentrated manner,

which can accelerate the maturation of the surface soil, shorten the reclamation

time, and reduce the reclamation cost.

[0019] Furthermore, by mixing the stripped topsoil with crushed straw and

fully decomposed organic fertilizer, and then spraying with compound microbial inoculum, the decomposition and transformation of pulverized coal in topsoil can be accelerated, and the soils can be cured, which promotes the formation of aggregate structure and improves the soil structure.

[0020] Pulverized coal contains a large amount of carbon, hydrogen, oxygen,

sulphur, silicon, aluminium, calcium, magnesium, phosphorus, potassium and

other elements. In that invention, the bacterial inoculum such as Bacillus

subtilis, Bacillus megaterium, Pseudomonas, penicillium and the like are used

for effectively utilizing the carbon source and various nutrient element in the

organic fertilizer and the pulverized coal, In addition, that insoluble nutrient

element are released into a water-soluble or citric acid-soluble form, which is

favourable for the absorption of crop.

[0021] Finally, the stripped topsoil was mixed with straw and organic fertilizer

to form a ridge belt, which was covered with plastic film and subjected to high

temperature and high humidity in rainy season, which accelerates the

mineralization and decomposition of coal powder, straw and organic fertilizer,

promotes the activation of soil nutrients, reduces the bulk density of 0 - 20cm

soil surface, increases the soil porosity, and increases the total amount of soil

microorganisms, and improves that physical and chemical properties of the

soil, and provides favourable water, fertilizer, gas and heat conditions for the

growth of crop in the second year.

[0022] The reclamation method of the present invention is reasonable in

design and simple in operation, and provides an effective solution for the safe

and efficient reclamation of abandoned coal storage yards in China, which can be popularized in the mining areas of the Loess Plateau of China and has high practical value and wide market prospects.

DESCRIPTION OF THE INVENTION

[0023] The following examples are only preferred technical solutions of the

present invention and are not used for any limitation of the invention. Various

modifications and variations of the invention will be apparent to those skilled

in the art. Any modification, equivalent substitution, improvement, etc. made

within the spirit and principle of the present invention should be included in

the protection scope of the invention.

[0024] Example 1.

[0025] The test site was selected from a waste coal storage yard in Xiaoyi

City, Shanxi Province. The coal storage yard was built in 1999 and abandoned

in May 2014, and has been in use for 15 years, mainly for coal turnover. The

coal storage yard covers an area of 1,785 m 2 and is irregular rectangular. The

area is hilly region of the Loess Plateau, with an average annual rainfall of

about 400mm and no irrigation conditions.

[0026] In this embodiment, the following implementation steps are adopted to reclaim the

waste coal storage yard.

[0027] 1) Site levelling: Before the rainy season, in the abandoned coal

storage yard proposed to be reclaimed, the surface shall be tidied manually

and mechanically, the available coal shall be collected, and then the stones

and sundries on the surface and in the soil shall be removed. And preliminary

levelling shall be carried out.

[0028] 2) Soil sampling and testing: Soil samples shall be collected at depths

of 0-20cm and 20-40cm by the grid method of OxOm. Air-dry the sample

and send it to the laboratory for analysis. The testing items include pH value,

organic carbon, total nitrogen, available phosphorus, available potassium,

bulk density and so on.

[0029] 3) Topsoil stripping: Use a high-powered bulldozer to strip the topsoil

containing pulverized coal from the cleaned coal storage yard, with a

stripping thickness of 20cm. The stripped topsoil shall be stacked conically

nearby, and the surface shall be covered with plastic cloth to prevent soil loss.

[0030] 4) Subsoil levelling: Bulldozer shall be used to level the stripped subsoil, with the

flatness meeting the drainage requirements and free of ponding.

[0031] 5) Mixed ridge soil: The stripped topsoil, fully decomposed chicken

manure, crushed corn straw and urea shall be thoroughly mixed according to

the mass ratio of 100: 1: 0. 5: 0 .005. The rotten chicken manure was supplied

by Shanxi Pingyao Guoqing Tongying Poultry Industry Co., Ltd., with the

organic matter content of 56%, and the corn straw was crushed into blocks

with the length of 1-5cm.

[0032] 6) Stacking the ridges: The mixed ridges are stacked in strips on the

subsoil. The stacked strips are 100cm in width and 30cm in height, and the

distance between two strips is 120cm, with compaction during stacking to

prevent collapse.

[0033] 7) Preparation of complex microbial inoculum: Beef extract 5.0g,

peptone 10.0g, NaCl 5g, water 1000ml were used as complex medium for

Bacillus subtilis, Bacillus megaterium and Pseudomonas sp. After inoculating

the bacteria liquid, it was cultured for 48 hours at pH 7.0 and 30°C in a shaking

table at 120r/min until the concentration of bacteria liquid was more than 10"

cfu/ml. Penicillium liquid culture medium: Culture potato 200g, glucose 20g,

MgSO4-7H20 1.5g, KH2PO4 3g, VB1 trace amount, distilled water 1000ml

for 48h at constant temperature 28C, in shaking table at 180r/min. In that

invention, two bacterial solution are mixed, and the effective viable bacteria

count is adjusted to 10x10 9cfu/ml to obtain a composite microbial inoculum.

[0034] 8) Spraying composite microbial inoculum: Dilute the above

mentioned compound microbial inoculum by 30 times, spray it on the ridge at

the application rate of 1-2L per mu, and control the soil humidity in the ridge

to keep the relative water content at 70% in order to fully react that composite

microbial inoculum with the soil.

[0035] 9) Film mulching: A silver-black two-color mulching film with a

thickness of 0.015mm was laid on the ridge belt, and a hole was made every

0.5m for air permeability. The mulching film is provided by Shandong

Qingzhou Jinpeng Agricultural Plastic Film Factory.

[0036] 10) Planting: In the middle of April of the next year, uncover the

plastic film, and apply 45% of the compound fertilizer (N-P205-K20 = 23:

12: 5) produced by Shanxi Chenyu Group on the ground in accordance with

the application amount of 50kg/mu, plough and then plant corn on the ridge.

[0037] In order to clarify the reclamation effect of the waste coal storage yard

treated by the method of this example, two treatments were tested. Control group: Directly arrange the abandoned coal storage yard, and plant it after ploughing, without stripping and ridging. Experimental group: Operate the land according to the method of this embodiment. The test was repeated 3 times and the plot area was 100m2

.

[0038] The sowing began on April 25, and the sowing method was on

demand, Dafeng 30, with row spacing of 60cm, plant spacing of 30cm, and

harvesting on October 12.

Table Investigation of soil physical and chemical properties

Organic Total Available Available Bulk Porosity, Process pH Carbon, nitrogen, phosphorus, potassium, density, g/kg g/kg mg/kg mg/kg g/cm

% Control 6.75 2.26 1.13 10.87 83.5 1.46 47.5 group Experimental 7.35 3.15 1.75 18.62 115.5 1.35 56.8 group

[0039] According to the investigation results of soil physical and chemical

properties after harvesting in Table 1, it can be seen that the soil pH value can

be adjusted by using the reclamation method of the present invention, which

avoids soil acidification. And it can increase the content of soil organic

carbon and total nitrogen, available phosphorus and available potassium, can

improve soil fertility, reduce the soil bulk density (0-20cm), can increase the

porosity (0-20cm) and permeability and can improve physical properties of

the soil.

[0040] The results of maize yield test show that compared with the control

group, the reclamation method of the present invention can improve the plant

height and stem diameter of maize, increase the yield by 41.5% and increase the benefit by 257.70 yuan per mu, and the reclamation effect is remarkable.

[0041] Example 2.

[0042] The test site was selected from an abandoned coal storage yard in

Table 2 Investigation on corn yield Plant Stem Yield Yield increase Net Process height diameter kg/mu rate benefit cm cm % yuan/mu Control Group 195.7 1.85 413.5

/ Experimental 216.5 2.16 585.5 41.5 257.7 Group Xiangyuan County, Shanxi Province. The coal storage yard was built in 2006

and abandoned in August 2015, where coal was piled in the open air, making

it a large-scale local coal freight transit station. The coal storage yard covers

an area of 4875 m 2 and is rectangular (7 8 x62.5m). The area is located in the

Shangdang basin, with relatively flat terrain, an average annual rainfall of

about 500mm, and good agricultural production conditions.

[0043] In this embodiment, the following implementation steps are adopted to reclaim the

waste coal storage yard.

[0044] 1) Site levelling: In the abandoned coal storage yard proposed to be

reclaimed, the surface shall be tidied manually and mechanically, the

available coal shall be collected, and then the stones and sundries on the

surface and in the soil shall be removed. And preliminary levelling shall be

carried out.

[0045] 2) Soil sampling and testing: Soil samples shall be collected at depths of 0-20cm

and 20-40cm by the grid method of lOx1Om. Air-dry the sample and send it to the

laboratory for analysis. The testing items include pH value, organic carbon, total nitrogen,

available phosphorus, available potassium, bulk density and so on.

[0046] 3) Topsoil stripping: Use a high-powered bulldozer to strip the topsoil containing

pulverized coal from the cleaned coal storage yard, with a stripping thickness of 20cm. The

stripped topsoil shall be stacked conically nearby, and the surface shall be covered with

plastic cloth to prevent soil loss.

[0047] 4) Subsoil levelling: Bulldozer shall be used to level the stripped subsoil, with the

flatness reaching 1/1000 - 1/1500.

[0048] 5) Mixed ridge soil: The stripped topsoil, fully decomposed chicken

manure, crushed corn straw and urea shall be well mixed according to the mass

ratio of 150: 1: 0. 5: 0 .005. The rotten chicken manure is provided by

Xiangyuan County breeding enterprise with organic matter content 51%. Corn

straw was crushed into lumps with a length of 1-5cm.

[0049] 6) Stacking the ridges: The mixed ridges are stacked in strips on the subsoil. The

stacked bar is 80cm wide and 30cm high, and the distance between two bar stacks is 100cm

with compaction during stacking to prevent collapse.

[0050] 7) Preparation of complex microbial inoculum: Beef extract 5.0 g,

peptone 10.0g, NaCl 5 g, water 1000ml were used as complex medium for

Bacillus subtilis, Bacillus megaterium and Pseudomonas sp. After inoculating

the bacteria liquid, it was cultured for 48 hours at pH 7.0 and 30°C in a shaking

table at 120r/min until the concentration of bacteria liquid was more than 10" cfu/ml. Penicillium liquid culture medium comprising potato 200g, glucose g, MgSO47H20 1.5g, KI2PO4 3 g, VB1 trace amount, and distilled water

1000ml, is cultured at constant temperature 28°C in 180r/min shaking table

for 48h. In that invention, two bacterial solution are mixed, and the effective

viable bacteria count is adjust to lOx1Ocfu/ml to obtain a composite

microbial inoculum.

[0051] 8) Spraying composite microbial inoculum: Dilute the above

mentioned compound microbial inoculum by 25 times, spray it on the ridge at

the application rate of 1 - 2L per mu, and control the relative water content of

the soil humidity in the ridge at 70%, in order to make that composite

microbial inoculum fully react with the soil.

[0052] 9) Film mulching: A silver-black two-colour mulching film with a

thickness of 0.015mm was laid on the ridge belt, and a hole was made every

0.5m for air permeability. The mulching film is provided by Shandong

Qingzhou Jinpeng Agricultural Plastic Film Factory.

[0053] 10) Planting: In late April of the second year, uncover the mulch, and

evenly spread the 45% compound fertilizer (N-P20-K20=23:12:5) produced

by Shanxi Chenyu Group at an application rate of 50 kg per mu then plow

and plant corn on the ridges.

[0054] In order to clarify the reclamation effect of the method of this

embodiment in treating abandoned coal storage yards, two treatments are set

up in the experiment. Control group: directly reorganize the abandoned coal

storage yard and plant after plowing without stripping or ridges. Experimental group: operate the land according to the method of this embodiment. The test was repeated 3 times, with a plot area of 150 m2

.

[0055] Planting began on May 3, and the planting method was on-demand,

the variety Jinping 618, the row spacing was 60cm, the plant spacing was

cm, and it was harvested on October 9. Irrigation, weeding, fertilization

and other measures are the same during planting.

Table 3 Investigation of soil physical and chemical properties Organic Total Available Available Bulk Process pH Carbon, nitrogen, phosphorus, potassium, density, Porosity, g/kg g/kg mg/kg mg/kg g/cm 3

Control 6.67 2.43 1.31 12.87 96.4 1.43 46.9 group

Experimental 7.25 3.67 1.96 21.62 123.7 1.29 57.2 group

[0056] According to the survey results of the physical and chemical

properties of the soil after harvest in Table 3, it can be seen that the

reclamation method of the present invention can adjust the soil pH value and

avoid soil acidification; increase the soil organic carbon content and the

content of total nitrogen, available phosphorus, and available potassium, and

improve the soil Fertility; reduce soil bulk density, increase porosity and

permeability, and improve soil physical properties.

Table 4 Investigation on corn yield Plant Stem diameter Yield Yield increase Net benefit Process height cm kg/mu rate yuan/mu cm %

Control 205.4 2.05 426.7 / Group /

Experimental 235.9 2.37 592.3 38.8 223.50 Group ______ ______ __

[0057] The results of corn test yields showed that compared with the control

group, using the reclamation method of the present invention can increase the

plant height and stem thickness of corn, the yield increase rate reached 38.8%,

the benefit per mu was 223.50 yuan, and the reclamation effect was

significant.

Claims (10)

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1.In that method for reclaiming the waste coal storage yard, the topsoil of the

proposed reclaimed coal storage field is stripped, mixed with straw and

decomposed organic fertilizer, and uniformly mixed to obtain ridge soil;

piling the ridge band on the bottom soil expose after stripping the surface soil

of the coal storage yard with the ridge soil, spraying the compound microbial

inoculum onto the ridge bands, and covering the ridges with the black plastic

film with pores; opening the plastic film in the next year, to grow crops on a

ridge.

2. The method for reclamation of waste coal storage yard according to claim

1 is characterized in that the mixing mass ratio of the stripped topsoil and the

straw, the decomposed organic fertilizer is 100: 0.25 - 1: 1 - 4.

3. A method for reclamation of a waste coal storage yard according to claim

1 or 2 is characterized in that the straw is crushed to length 1-5cm of corn

straw or sorghum straw.

4.The method for reclamation of a waste coal yard according to claim 1 is

characterized in that the decomposed organic fertilizer is any one of cow, pig,

chicken, sheep manure, or any mixture of several.

5.The waste coal yard reclamation method according to claim 1 is

characterized in that the stripping thickness of the topsoil is 20 to 30 cm.

6.The method for reclamation of a waste coal storage yard according to claim

1 is characterized in that each 100 tons of the ridge soil is added with 3-8 kg

of urea.

7.The method for reclamation of a waste coal storage yard according to claim

1 is characterized in that the width of the stacked ridges is 80-100cm, height

is 30-40cm, and ridge spacing is 80-120cm.

8. The method for reclamation of waste coal storage yard according to claim

1 is characterized in that the composite microbial inoculum is a mixed

microbial inoculum prepared by mixing Bacillus subtilis, Bacillus

megaterium, Pseudomonas and Penicillium.

9. The method for reclamation of a waste coal storage yard according to

claim 1 is characterized in that the film is provided with a gas permeable hole

every 0.5 m.

10. The method for reclamation of a waste coal storage yard according to

claim 1 is characterized in that crop corn is planted on a ridge.