Over many decades, cement has been the primary component in construction projects and is considered one of the essential industries worldwide. At the same time, it overconsumes natural resources and can negatively impact the environment through a few byproducts, such as carbon dioxide (CO₂) and cement kiln dust (CKD). The generated quantity of CKD is estimated to be 15–20% of the produced cement, which means CKD can be induced in hundreds of millions of metric tons synchronously with annual global cement production. Unfortunately, not all materials of CKD are suitable for recycling in cement manufacturing since it contains high levels of alkalis, sulfate, and chloride, leading to excessive concentrations in the final product. Therefore, CKD industrial utilization has become highly recommended in recent research as a potential beneficial application from economic, environmental, and sustainability perspectives. This review paper highlights and discusses the recently conducted research articles that investigate the industrial applications of CKD. The obtained outcomes showed that CKD has physical and chemical properties that make it practical in many fields, such as soil stabilization, concrete mix, chemical treatment, ceramic and brick manufacturing, and mine backfill. They also indicate a lack of studies investigating CKD in mine backfill applications as a partial replacement material for cement due to the high cost of binders, optimization, and sustainability purposes.

The conventional blasting rock excavation method is the main means of rock breakage because of its high productivity, and it is relatively inexpensive compared to other methods. However, it raises safety concerns and can negatively impact the environment. The major disturbances that may be induced by this method include flyrock, gas emissions, and vibrations. This review discusses some nonexplosive rock breakage methods, particularly the hydraulic splitter and expansive chemical agents, that can be employed instead of the conventional blasting method and analyzes their potential effectiveness in rock breakage. Hydraulic splitting machines and expansive chemical agents were studied in the context of the literature. This review showed that hard rock breaking can be executed effectively and safely using alternative methods, which have a wide range of advantages, including safe operation, ease of use, and environmental friendliness, over conventional explosive methods. Moreover, as modern nonexplosive methods, hydraulic splitting machines and expansive chemical agents can generate pressure of up to 43 and 30–44 MPa to induce stresses in rocks, respectively. Owing to safety and environmental restrictions on conventional blasting, the application scope of the modern methods can be increased in the future.

The Kingdom of Saudi Arabia covers an area of approximately 2 million km² and is rich in natural resources that are necessary for industrial development. The estimated mineral wealth beneath the Kingdom’s soil is approximately USD 1.33 trillion, as reported by the Ministry of Industry and Mineral Resources. The Kingdom’s vision for 2030 is to develop the mining sector to become the third pillar of the domestic economy. Therefore, exploration and mining activities are expected to accelerate over the next decade, which will lead to increased waste production. New executive regulations issued in January 2021 contain several sustainable elements related to the environment, social responsibility, and occupational health and safety. Therefore, this study aims to promote an example of sustainable mining activities in the Kingdom that could be adapted to meet the regulatory requirements. Cemented paste backfill samples of varying composition were made with waste materials from a Saudi copper mine for re-injection into underground mining cavities to minimize waste exposure to the environment. The samples were tested for unconfined compressive strength (UCS) after 7, 14, 28, 56, and 90 days of curing. Results from a statistically designed experiment technique show that the samples developed sufficient strength to be used in mine backfilling applications. Strong negative relationships were detected between the UCS and the water-to-binder ratio. There is strong potential for mine backfill technology to be applied to a wide range of Saudi Arabian mines to enhance the sustainability of the mining sector.

This study aims to develop a novel mine backfill material called foam mine fill (FMF). A cellular structure is achieved by incorporating a premade foam into the backfill mixture using an air-entraining agent. FMF samples were prepared with copper-nickel mine tailings and normal Portland cement. Experiments were designed to investigate the effect of binder dosage, volume of entrained air, and foam mixing time on FMF unconfined compressive strength (UCS) and dry density. Moreover, a qualitative microscopic assessment investigated the effect of foam mixing time on air bubble structure. The pore size distribution and porosity of selected samples were investigated through mercury intrusion porosimetry. Relative to reference samples without entrained air, the UCS of FMF samples was 20–50% lower. However, the concomitant lower dry density (by up to 360 kg/m³) could enhance the safety of the underground working environment, especially in underhand cut-and-fill mining where miners and machinery work beneath the backfilled stope, and lower-density fill material would minimize the adverse effects of potential backfill failure. Prolonged foam mixing time led to a significant loss in UCS and total collapse of the air bubble structure. Other potential applications for FMF are areas where there are tailings shortages and as an alternative to hydraulic fill.

Pyrophyllite (Al₂Si₄O₁₀(OH)₂) is a phyllosilicate often associated with quartz, mica, kaolinite, epidote, and rutile minerals. In its pure state, pyrophyllite exhibits unique properties such as low thermal and electrical conductivity, high refractive behavior, low expansion coefficient, chemical inertness, and high resistance to corrosion by molten metals and gases. These properties make it desirable in different industries such as refractory; ceramic, fiberglass, and cosmetic industries; as filler in the paper, plastic, paint, and pesticide industries; as soil conditioner in the fertilizer industry; and as a dusting agent in the rubber and roofing industries. Pyrophyllite can also serve as an economical alternative in many industrial applications to different minerals as kaolinite, talc, and feldspar. To increase its market value, pyrophyllite must have high alumina (Al₂O₃) content, remain free of any impurities, and possess as much whiteness as possible. This paper presented a review of pyrophyllite’s industrial applications, its important exploitable properties, and the specifications required for its use in industry. It also presents the most effective and economical techniques for enriching low-grade pyrophyllite ores to make them suitable for various industrial applications.