(b) Strengthening the comprehensive use of bulk solid waste We will enhance the comprehensive utilization level and increase the multipurpose utilization rates of mineral resources. We will support the large-scale utilization of waste in manner that maximizes proportion and value with a focus on bulk solid wastes including coal gangue, coal fly ash, tailings, associated minerals, smelting slag, byproduct gypsum, construction refuse, and crop straw, and encourage the use of such waste as a substitute for raw non-metallic minerals and gravel. On the condition of being safe and eco-friendly, we will explore the use of phosphogypsum in improving soil, back filling underground mines, and preparing sub-grade for roads. The recycling of construction wastes will be promoted, and the in-situ reclamation and use of abandoned pavement materials will be widely applied. We will accelerate the recycling of crop straw in a way that maximizes its value by refining systems for purchase, storage, and transportation, while strictly enforcing the burning ban. We will also speed up efforts to carry out demonstration projects for the comprehensive utilization of bulk solid waste. By 2025, the amount of bulk solid waste recycled annually will reach around 4 billion metric tons, rising to about 4.5 billion by 2030. (c) Refining systems for resource recycling