随着矿业、冶金和化工等行业在我国的飞速发展，工业固体废弃物不仅产量大、处理成本高，并且污染严重，如何实现固体废弃物的资源化利用是我国面临的一个重要环境问题。充填开采既有助于实现矿井安全开采，又有利于从源头上解决地下水流失、地表沉陷、土地占用损害等井下开采所造成的环境污染难题，但是充填成本过高限制了充填开采运用于矿山实际。矿井充填实践表明单一养护温湿度实验并不能准确预测井下不同温湿度养护环境下充填体的强度发展，不同养护条件凸显出充填材料配比设计不合理的问题。有效降低矿山充填成本、实现固体废弃物资源化利用及设计更为合理的充填材料配比以实现充填开采的广泛应用是当今的主要研究方向。

本文以改性镁渣和粉煤灰为胶凝材料完全替代水泥，煤气化渣为骨料制备改性镁-煤渣充填材料（M-CSPB），在有效降低充填成本的同时实现了固体废弃物的资源化利用。通过单轴压缩、数字散斑、热重、电镜扫描和X射线衍射等实验方法对不同温湿度养护条件下M-CSPB宏观力学性能、变形破坏和微观结构展开研究，揭示了不同温湿度条件下M-CSPB强度变化规律、变形破坏规律及微观结构特征，为根据矿山情况合理设计充填材料配比提供理论依据。主要有以下结论：

（1）标准湿度养护时，低温养护条件下（20℃）M-CSPB早期强度发展缓慢，后期强度发展较快，FA掺量为20%条件下M-CSPB强度从养护时间为7 d时0.96 MPa增加到56 d时6.45 MPa；温度升高，强度增长明显，30℃时7 d与56 d强度分别为2.53 MPa与8.52 MPa，温度升高至40℃，M-CSPB养护 7 d强度为5.74 MPa，56 d强度为6.21 MPa。表明温度升高有利于M-CSPB强度发展，但是高温（40℃）不利于M-CSPB后期强度发展。

（2）在低温养护时，高湿度（95%）不利于M-CSPB强度发展，以20%FA掺量为例，低湿度（50%）养护条件下M-CSPB在养护时间为7 d、14 d、28 d和56 d分别比高湿度条件下强度增加了0.77 MPa、-0.14 MPa、1.90 MPa和1.51 MPa。然而，高湿度的负面影响会随着FA掺量增得到改善；而养护温度升高至30℃与40℃，较高温度对M-CSPB强度产生不利影响出现的时间随湿度降低有所提前。井下养护时如果温度较低可以适当降低环境湿度来提高M-CSPB强度，温度较高时则应该保证充填材料处于湿度较高环境下。

（3）M-CSPB试件破坏形式主要为拉伸破坏，应力-应变曲线随FA掺量增加、温度升高与湿度降低变的更加尖锐。同等养护条件下FA掺量为0%、20%和40%时脆性系数分别为0.17、0.20和0.22；养护温度从20℃增加至40℃时，M-CSPB脆性系数从0.22增加至0.38；低湿度条件下M-CSPB试件脆性系数在FA掺量较低时较高湿度条件下更低，随着FA掺量增加，低湿度条件下M-CSPB试件脆性系数要高于高湿度条件下脆性系数。表明M-CSPB试件破坏形式随FA掺量增加、温度升高与湿度降低趋向于脆性，同时弹性模量大小亦随FA掺量增加、温度升高与湿度增加而增加。

（4）温湿度养护条件与FA掺量得变化没有改变M-CSPB水化产物类型，但是影响水化产物生成量。一定条件下，水化产物生成量随FA掺量和湿度增加而增加，相应的孔径分布曲线峰值亦向右移动，无害孔体积占比增加，有害孔与多害孔占比减小。水化产物数量亦随温度升高而增加，但是温度升高对M-CSPB内部孔隙发展有不利影响。

With the rapid development of industries such as mining, metallurgy, and chemical industry in China, industrial solid waste not only has a large output, high treatment costs, but also serious pollution. How to achieve the resource utilization of solid waste is an important environmental problem that China is facing. Backfill mining not only helps to achieve safe mining in mines, but also helps to solve the environmental pollution problems caused by underground mining such as groundwater loss, surface subsidence, and land occupation damage from the source. However, the high backfill cost limits the practical application of backfill mining in mines. The practice of mine backfill shows that a single maintenance temperature and humidity experiment cannot accurately predict the strength development of backfill materials under different temperature and humidity maintenance environments underground. Different maintenance conditions highlight the problem of unreasonable design of backfill material proportions. The main research direction today is to effectively reduce mining backfill costs, achieve the resource utilization of solid waste, and design more reasonable backfill material ratios to achieve widespread application in backfill mining.

In this paper, modified magnesium slag and fly ash are used as cementitious materials to completely replace cement, and Coal gasification slag is used as aggregate to prepare modified magnesium-cinder backfill material (M-CSPB), which can effectively reduce the backfill cost while realizing the resource utilization of solid waste. The macroscopic mechanical properties, deformation failure, and microstructure of M-CSPB under different temperature and humidity curing conditions were studied through experimental methods such as uniaxial compression, digital speckle, thermogravimetry, electron microscopy scanning, and X-ray diffraction. The changes in strength, deformation failure, and microstructure characteristics of M-CSPB under different temperature and humidity conditions were revealed, providing a theoretical basis for designing the backfill material ratio reasonably based on the mine situation. The main conclusions are as follows:

(1) During standard humidity curing, under low temperature curing conditions (20 ℃), the early strength development of M-CSPB is slow, while the later strength development is fast. Under the condition of 20% FA content, the strength of M-CSPB increases from 0.96 MPa at 7 days of curing time to 6.45 MPa at 56 days. As the temperature increases, the strength increases significantly. At 30 ℃, the strength at 7 days and 56 days is 2.53 MPa and 8.52 MPa, respectively. When the temperature rises to 40 ℃, the strength of M-CSPB cured at 7 days is 5.74 MPa, and the strength at 56 days is 6.21 MPa. It indicates that an increase in temperature is beneficial for the strength development of M-CSPB, but high temperature (40 ℃) is not conducive to the later strength development of M-CSPB.

(2) During low-temperature curing, high humidity (95%) is not conducive to the development of M-CSPB strength. Taking 20% FA content as an example, under low humidity (50%) curing conditions, the strength of M-CSPB increased by 0.77 MPa, -0.14 MPa, 1.90 MPa, and 1.51 MPa at 7 days, 14 days, 28 days, and 56 days, respectively, compared to high humidity conditions. However, the negative impact of high humidity will be improved with the increase of FA dosage; However, when the curing temperature increases to 30 ℃ and 40 ℃, the adverse effect of higher temperature on the strength of M-CSPB occurs earlier with the decrease of humidity. If the temperature is low during underground maintenance, the environmental humidity can be appropriately reduced to improve the strength of M-CSPB. When the temperature is high, it should be ensured that the backfill material is in a high humidity environment.

(3) The main failure mode of M-CSPB specimens is tensile failure, and the stress-strain curve becomes sharper with increasing FA content, increasing temperature, and decreasing humidity. Under the same curing conditions, the brittleness coefficients are 0.17, 0.20, and 0.22 when the FA content is 0%, 20%, and 40%, respectively. When the curing temperature increases from 20 ℃ to 40 ℃, the brittleness coefficient of M-CSPB increases from 0.22 to 0.38; The brittleness coefficient of M-CSPB specimens under low humidity conditions is lower under higher humidity conditions when the FA content is low. As the FA content increases, the brittleness coefficient of M-CSPB specimens under low humidity conditions is higher than that under high humidity conditions.

(4) The changes in temperature and humidity curing conditions and FA dosage did not change the type of hydration products of M-CSPB, but affected the amount of hydration products generated. Under certain conditions, the generation of hydration products increases with the increase of FA content and humidity, and the corresponding peak of pore size distribution curve also shifts to the right. The proportion of harmless pores increases, while the proportion of harmful and multi harmful pores decreases. The number of hydration products also increases with increasing temperature, but the increase in temperature has a negative impact on the development of internal pores in M-CSPB.