Method for solidifying tailings sand based on active magnesium oxide microorganisms and products thereof

A technology of activated magnesia and tailings sand, which is applied in the field of tailings sand solidification, can solve problems such as difficulty in ensuring the uniformity of solidified samples, high heavy metal content in tailings sand, and easy cracks on the sample surface, achieving good application prospects and reducing heavy metals The effect of ion content and strength improvement

Active Publication Date: 2021-10-22
CHONGQING UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, there are some problems in this method. CO2 is introduced into the carbonization barrel under a certain pressure. 2 , the surface of the sample is prone to cracks, and the carbonization of the sample proceeds from the surface to the inside. It is difficult to ensure the uniformity of the solidified sample, and CO 2 The operation process is relatively complicated, and it is limited in practical application, so it is not suitable for the solidification of large amounts of tailings sand.
Moreover, the heavy metal content in the tailings sand is high, so it cannot be directly used for land reclamation, construction materials, glass and ceramics, etc.

Method used

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  • Method for solidifying tailings sand based on active magnesium oxide microorganisms and products thereof
  • Method for solidifying tailings sand based on active magnesium oxide microorganisms and products thereof
  • Method for solidifying tailings sand based on active magnesium oxide microorganisms and products thereof

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Experimental program
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Effect test

Embodiment 1

[0029] Embodiment 1, the cultivation of bacteria

[0030] The method of bacterial culture is as follows: take Bacillus strains, after being activated by streaked plate culture, pick a single colony for preliminary expansion culture, and then inoculate it into a Erlenmeyer flask for amplified culture, and cultivate it to the logarithmic growth phase. The urease activity is 2.4mmol urea / (L·min), spare. The main components of the culture medium used by bacteria are as follows: 20g / L peptone, 10g / L urea, 5g / L sodium chloride.

Embodiment 2

[0031] Embodiment 2, the preparation of brick mold

[0032] In order to carry out the solidification experiment better, a brick-making mold for magnesia microbial solidification tailings sand was designed and processed. The box (240×115mm) and the left and right side panels (240×53mm) are evenly arranged with circular holes with a diameter of about 1.0cm, which can adjust the micro-expansion of the solidified tailings sand, and is conducive to the discharge of water and CO in the air. 2 The absorption; the internal size is 240×115×53mm (standard brick size), the assembled mold is as follows figure 1 shown. The brick-making mold adopts a combined structure, is easy to disassemble and can be used repeatedly.

Embodiment 3

[0033] Embodiment 3, the solidification of tailings sand adds

[0034] Get the bacillus 200ml that embodiment 1 cultivates, adopt activity (iodine absorption value) to be 250g of active magnesium oxide of 120, add the urea solution 400ml that concentration is 3mol / L, get the tailing sand 2250g of certain manganese slag tailings pond, dry Finally, remove particles and sundries with a particle size greater than 1cm; first mix 250g of active magnesium oxide and 2250g of tailings sand evenly, then mix and stir with urea solution, then add bacterial solution and mix evenly, then pour into the mold, and layer and compact to Design dry density 1.7g / L, let stand for 6 hours, the result is as follows figure 2 shown. After curing, the mold is removed, and the surface is polished to obtain cured tailings sand bricks, such as image 3 shown. It can be seen from the figure that the bricks after demoulding are complete and the surface is relatively smooth, and the curing condition is go...

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Abstract

The invention discloses a method for solidifying tailings sand based on active magnesia microorganisms and its products. Active magnesia is used as the basic curing agent, and microbial technology is used to provide CO required for carbonization. 2 and reduce the heavy metals in the tailings sand, making full use of the advantages of magnesium oxide solidified soil technology and microbial technology, using the carbonate ions produced by the hydrolysis of urea by Bacillus to carbonize the magnesium oxide solidified soil, improving the strength of the brick body, and using The extracellular complexation, extracellular precipitation and intracellular accumulation of heavy metals by microorganisms can reduce the content of heavy metal ions. The method has the advantages of simple process, no sintering, short construction period, high strength, environmental protection, can realize win-win of environmental benefit and economic benefit, and has good application prospect.

Description

technical field [0001] The invention relates to the field of tailing sand solidification, in particular to a method for solidifying tailing sand based on active magnesium oxide microorganisms and a product thereof. Background technique [0002] Activated magnesia (MgO) is a low-carbon and environmentally friendly curing agent proposed in recent years. Carbonization and curing technology can achieve the required strength in a short time, but the curing of activated magnesia requires a large amount of CO 2 reaction. At present, in order to solve the CO required for the curing of active magnesia 2 , Liu Songyu et al. used pressure to inject CO 2 method to carbonize it. However, there are some problems in this method. CO2 is introduced into the carbonization barrel under a certain pressure. 2 , the surface of the sample is prone to cracks, and the carbonization of the sample proceeds from the surface to the inside. It is difficult to ensure the uniformity of the solidified s...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C04B28/10
CPCC04B28/105C04B2201/20C04B2201/50C04B18/12C04B24/126C04B2103/0001
Inventor 方祥位方艺霏杨阳陈哲申春妮
Owner CHONGQING UNIV
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