本文针对陕北地区煤矸石在道路工程中高效利用的关键技术问题，以陕北侏罗纪煤田典型矿区-大保当、巴拉素、大柳塔地区的煤矸石为研究对象，分析了其理化性质、矿物组成及微观结构特征，研发了针对性强的路用煤矸石分选工艺，并结合实际工程应用进行了验证。主要研究内容与结论如下：

（1）通过煤矸石基本理化性质与力学性能测试，分析了陕北地区不同矿区煤矸石在密度、吸水率、压碎值、单轴抗压强度、针片状含量、膨胀率及烧失量等方面的差异。并结合傅里叶红外光谱（FTIR）、扫描电镜（SEM）微观分析手段，进一步分析了煤矸石的矿物组成与微观结构差异性，为后续选择性破碎特性研究提供了理论依据。

（2）深入探究了煤矸石选择性破碎的机理及规律，确定了矿物硬度差异是实现选择性破碎的前提条件，提出以鄂式破碎-锤式破碎组合工艺为基础的选择性破碎工艺，验证了该工艺能有效实现煤矸石中硬质矿物的富集，通过鄂式-锤式组合破碎处理后，粗集料中石英含量增加6.7%，高岭石含量由21.72%降低至9.65%，提升了集料性能及品质。

（3）基于选择性破碎理论，设计开发了包含粗碎、中碎、自磨整形及振动筛分功能的模块化路用煤矸石分选设备，进行了设备结构与工艺参数的优化设计，并制造了工程应用样机，验证表明了该设备能高效稳定地完成煤矸石分选及整形作业，提升了煤矸石作为道路材料的综合性能。

（4）通过在G307国道靖边至定边段改扩建工程中的试验路铺筑，评估了分选后的煤矸石作为水泥稳定基层材料的实际应用效果。现场施工与质量检测表明，分选后的煤矸石弯沉值优于规范要求，钻芯样品无侧限抗压强度达到4.2MPa，基层结构整体表现出良好的承载能力与稳定性，验证了分选工艺的实际应用价值。

研究结果表明，本研究提出的煤矸石路用分选工艺及装备能够有效提升煤矸石的资源化利用水平，改善了煤矸石道路材料的工程适应性，为陕北地区煤矸石在道路工程领域的规模化、高质量应用提供了坚实的技术支持与理论依据，对推动区域公路建设可持续发展具有重要的现实意义和推广应用价值。

This study focuses on the key technical issues related to the efficient utilization of coal gangue in road engineering in Northern Shaanxi. Coal gangue samples from the Dabaodang, Balasu, and Daliuta coal mines in Yulin, Shaanxi Province, China, were selected as the research objects. Their physical and chemical properties, mineral composition, and microstructural characteristics were systematically analyzed. A targeted separation process for road-oriented coal gangue was developed and further validated through practical engineering applications. The main work contents are as follows:

(1) Through comprehensive testing of the basic physical, chemical, and mechanical properties of coal gangue—including density, water absorption, crushing value, uniaxial compressive strength, needle-flake content, expansion rate, and loss on ignition—this study revealed the interregional variations among coal gangue from different mining sites. Combined with Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM), further analyses were conducted to elucidate the differences in mineral composition and microstructure, providing a theoretical basis for the subsequent investigation of selective crushing behavior.

(2) The mechanism and pattern of selective crushing were deeply explored. It was determined that differences in mineral hardness are the fundamental condition for achieving selective fragmentation. A combined crushing process, based on a jaw crusher followed by a hammer crusher, was proposed. Experimental validation confirmed that this process effectively enriches hard minerals in the coarse aggregate: the quartz content increased by 6.7%, while the kaolinite content decreased from 21.72% to 9.65%, thereby improving the overall quality and performance of the aggregate.

(3) Based on the theory of selective crushing, a modular separation device was designed and developed. The equipment integrates functions such as coarse crushing, intermediate crushing, self-grinding shaping, and vibrating screening. The structure and process parameters were optimized, and an engineering prototype was fabricated. Validation results show that the equipment can efficiently and steadily perform coal gangue separation and shaping, thereby improving the overall performance of coal gangue as a road construction material.

(4) A trial road section was constructed as part of the reconstruction project along the G307 National Highway (Jingbian–Dingbian section) to evaluate the practical applicability of the separated coal gangue as cement-stabilized base material. Field construction and quality inspection demonstrated that the compactness of the coal gangue base layer exceeded 97%, the measured deflection values were significantly better than the specification limits, and the unconfined compressive strength of core samples reached 4.2 MPa. The base structure exhibited excellent load-bearing capacity and stability, fully validating the practical value of the proposed separation process.

In conclusion, the separation process and equipment for road-oriented coal gangue developed in this study significantly enhance the resource utilization level of coal gangue. The proposed method not only improves the engineering adaptability of coal gangue as a road material, but also provides solid technical support and theoretical guidance for its large-scale and high-quality application in road engineering across Northern Shaanxi. The findings offer valuable reference for promoting the sustainable development of regional highway construction and the comprehensive utilization of industrial solid waste.