In recent years, great progress has been made in the development and utilization of nonmetallic minerals in China. Henan is rich in nonmetallic mineral resources, and its development and utilization are also increasing year by year. However, it still focuses on selling raw ore and rough machining, with low utilization rate and serious waste of resources. The damage to the environment has also attracted attention. It is imperative to strengthen the comprehensive utilization and protection of mineral resources.
I. Protection of nonmetallic mineral resources
Due to the problems of scientific and technological level, equipment and management, the development and utilization of nonmetallic mineral resources in Henan Province is not high. However, due to the imperfection of legal system and management, some resources are wasted and destroyed. Therefore, it is necessary to make overall planning for the non-metallic mineral resources in the whole province, and manage and protect the mineral resources according to law on the basis of planning.
1. nonmetallic mineral resources planning
(1) Improve laws and regulations and clarify the legal status of mineral resources planning. In 2000, the Ministry of Land and Resources of the State Council issued the Measures for the Management of Mineral Resources Planning, which provided a normative document for China's mineral resources planning. In the revision of "Detailed Rules for the Implementation of Mineral Resources Law" in the State Council, we should revise the corresponding clauses, standardize the preparation and approval procedures of mineral resources planning, and make it clear that mineral resources planning is a prerequisite for setting mining rights. On the basis of national laws and regulations, Henan Province should also put forward a systematic plan for the compilation, approval and management of mineral resources planning in Henan Province.
(2) On the basis of national mineral resources planning, Henan Province should make mineral resources planning according to the requirements of laws and regulations. As for nonmetallic minerals, planning opinions should be put forward for nonmetallic minerals such as cement limestone, granite, marble decorative materials and perlite, metallurgical auxiliary minerals such as refractory clay, kyanite and graphite, and chemical and other minerals such as dushan jade, bentonite, rutile, chemical limestone and barite.
(3) According to the occurrence, development and application of nonmetallic minerals, the regional planning is put forward. For example, Xinyang should plan volcanic nonmetallic mineral areas (bentonite, zeolite, perlite, etc.). ), Nanyang should plant kyanite, andalusite, cassiterite and rutile, and cities in western and northern Henan should plant limestone and refractory clay.
2. Strengthen the legal system construction, maintain the mining order, and ensure the rational utilization and protection of mineral resources.
(1) In the legislation of mineral resources planning, the legal status of planning in the process of setting mining rights should be clearly defined, and the setting of mining rights must obey the guidance of planning, and the mining rights that violate the planning should be revoked.
(2) Governments at all levels should strengthen law enforcement, resolutely ban unlicensed mining, and make up their minds to rectify those mining areas with long-standing mining order problems. Only when the mining order is fundamentally improved can the implementation of the plan and the protection of resources be guaranteed.
Second, adhere to the strategy of sustainable development, establish environmental awareness, and closely combine mining development with ecological environmental protection.
1. Protect the natural landscape and prevent disasters and environmental pollution caused by mining mineral resources.
(1) Non-metallic minerals are widely exploited in Henan Province, especially limestone, which is widely exploited as building materials such as cement limestone and flux limestone, and most of them destroy the natural landscape to varying degrees. Some areas as tourist attractions, such as Chaya Mountain and Yuntai Mountain, are often landscapes formed by granite and limestone, which are good building materials. Some ornamental caves are often caves in limestone areas. Therefore, it is an important task to plan and manage these tourism resources together with the tourism management department and the environmental protection department so that the beautiful natural landscape will not be destroyed.
(2) If the mining process of mineral resources is not handled properly, it will lead to a series of disasters. For example, underground mining leads to ground collapse, unreasonable surface mining leads to mining face collapse, improper stacking of waste residue and rock leads to rolling or debris flow in rainy season, and improper storage of tailings also leads to debris flow due to heavy rain. These problems have occurred in Henan province in recent years. Therefore, we must adhere to the approved mining design before mine construction, and determine the scientific and reasonable mining scheme and the treatment of waste rock, waste residue and tailings.
(3) It has been stipulated in the laws and regulations of mineral resources to establish the system of recovering landforms and reclaiming land while mining. However, due to the lack of effective and operable institutional measures, most mining enterprises are inefficient and difficult to implement. Therefore, the land and resources management department should strengthen the construction of this system and promote the effective development of this work.
(4) The environmental pollution caused by the mining and processing of nonmetallic minerals includes air and water, cement production and calcination of refractory clay minerals. The grinding of some nonmetallic minerals will cause dust and harmful gases to pollute the air. Ore mining wastewater can also pollute surface water and groundwater, such as wastewater from graphite concentrator, which is quite serious. Although people's awareness of environmental protection has been greatly enhanced, environmental protection measures in mine design have also been specially elaborated, but due to the low technical level and ineffective control measures, it is often unsatisfactory. Strengthening management, improving technical level and eliminating pollution are important tasks in the future.
2. Utilization of secondary resources
Natural resources include environmental resources, mineral resources and biological resources, collectively referred to as primary resources.
A large amount of waste discharged and discarded by human production and life, including waste water, waste gas and solid waste, is called waste. Waste is not useless, but temporarily useless, and human beings are fully capable of turning these wastes into new resources. These "three wastes" that can be used by human beings for the second time are collectively called secondary resources.
Utilization of waste rock and tailings.
The surrounding rocks and rocks with no industrial value produced during stripping and mining in mining process are called waste rocks, and the residual waste residue after ore dressing produces concentrate becomes tailings. Waste rock and tailings are solid wastes produced by mining. Because the surrounding rocks and ore compositions of different minerals are different, the composition of waste rocks and tailings is also different, and the development and utilization direction is also different. Generally speaking, there are the following aspects.
(1) Improve the technical level and management level to improve the mining recovery rate, mineral processing recovery rate and reduce the dilution rate, and study the comprehensive gravity separation process according to the tailings composition in mineral processing.
(2) making underground filling materials. Tailings and waste residue can be cemented with cement to make underground goaf filling materials, paving materials and pit filling materials.
(3) Using nonmetallic minerals, many waste rocks and tailings contain various nonmetallic minerals, such as silica, quartz, feldspar, various clays or kaolin, dolomite or limestone, serpentine, etc. , you can use. The comprehensive research institute of the former Ministry of Geology and Mineral Resources developed a kind of glass-ceramic granite product superior to natural granite by using potash feldspar tailings.
(4) Making building materials, such as making tailings bricks or making tailings sand aerated concrete. Tailing brick is made of tailings sand as the main raw material (65% ~ 67%), fly ash (15% ~ 20%), ground lime (8% ~ 12%) and gypsum (3%) as the activator, through stirring, grinding, molding and steam curing. See table 4-2- 1 for its performance.
Table 4-2- 1
Tailing sand aerated concrete is a lightweight porous building material, which is made of cement (16% ~ 18%), slag powder (32% ~ 34%), tailing sand (48% ~ 52%) and aerated agent in proportion.
The production process is as follows: raw material processing and preparation → batching and pouring → blank static cutting → steam curing → product taking out of the kettle. Concrete has the advantages of light volume and good thermal insulation performance, and its performance is shown in Table 4-2-2. It can be used as enclosure structure and partition wall of general industrial and civil buildings.
Table 4-2-2 Performance of Aerated Concrete
2) Treatment and utilization of mine wastewater
(1) wastewater classification. The composition of wastewater is very complex, and its properties vary widely. Every kind of wastewater is a combination of many impurities and several pollution indicators, which are often described and classified by one or two pollution factors. Because of the different sources, production methods, characteristics and forms of pollutants, the classification methods are also different.
The wastewater produced during the mining and processing of nonmetallic mines in Henan Province can be divided into two categories according to the degree of pollution.
Category I: Mine industrial wastewater, including mining and mineral processing wastewater and clean wastewater. Production wastewater is directly discharged in the production process. Water is in direct contact with minerals, raw materials, medicines, semi-finished products, finished products or equipment, carrying a lot of impurities or pollutants. This kind of wastewater is seriously polluted and harmful. Clean wastewater is the cooling water in production, which does not contact with pollutants, but the water temperature rises slightly.
The second category: mine domestic sewage and runoff sewage.
(2) Classification of wastewater treatment methods. The method of wastewater treatment varies with the nature of pollutants contained in wastewater and the use of circulating water. According to the principle of action, methods can be divided into four categories.
A. physical governance law. This is the most commonly used technology to purify and treat wastewater, which can be used as an independent treatment method, as a pretreatment method of chemical method, physical-chemical method and biochemical method, and even become an inseparable part of these methods.
Physical treatment is mainly used to separate and recover suspended solids in wastewater, and the composition and properties of pollutants are not changed during the treatment. However, for most wastewater, the ideal effect is often not achieved after treatment, and it needs to be combined with other treatment methods. However, the equipment of this treatment method is relatively simple, easy to operate, has a good separation effect on some wastewater, and is widely used.
B. chemical treatment. Through chemical reaction, the chemical properties and state of pollutants in wastewater can be changed, and pollutants such as colloidal substances and soluble substances in wastewater can be separated and recovered to eliminate their toxicity.
Chemical treatment requires chemicals or materials, so the treatment cost is high and the operation management is strict. Generally, chemical treatment needs to be combined with physical treatment. For example, before wastewater treatment, precipitation or filtration is often used as pretreatment; In some cases, it is necessary to carry out post-treatment by precipitation and filtration.
C. physical and chemical treatment methods. In the process of wastewater treatment, the process of transferring pollutants from one phase to another, that is, mass transfer process, is often used to separate soluble substances in wastewater and recover useful components, so that wastewater can be deeply purified. This treatment method is most effective when specific substances or toxic, harmful pollutants that are not easily degraded by microorganisms are recovered from wastewater.
D. biochemical treatment. In the process of wastewater treatment, a large number of microorganisms in nature have the function of oxidizing and decomposing organic matter and transforming it into inorganic matter. Through certain artificial measures, an environment conducive to the growth and reproduction of microorganisms is created to improve the efficiency of decomposing oxidized organic matter and achieve the purpose of purifying wastewater.
Practice shows that using microorganisms to treat organic matter in industrial wastewater has the advantages of high efficiency and low operating cost, and the decomposed sludge can be used as fertilizer. Therefore, it is mainly used to remove dissolved or colloidal organic pollutants from wastewater.
(3) Classification of wastewater treatment degree. The degree of wastewater treatment is generally divided into primary, secondary and tertiary treatment.
A. first-level governance. Mechanical methods and simple chemical methods are often used to remove suspended solids or colloidal substances, oil slick, neutral acid and alkali, adjust pH value, etc. They are both primary treatments and are often used as the preparation stage for further treatment. For wastewater with slight heavy metal pollution, it can be used as the main treatment form Generally, after primary treatment, the removal rate of suspended solids is 70% ~ 80%, while the removal rate of BOD is only 20% ~ 30%, so the purification degree of wastewater is not high.
B. Secondary governance. After preliminary treatment, the wastewater also contains a lot of dissolved pollutants, colloids, chlorides and sulfides. The task of secondary treatment is mainly to remove organic pollutants from wastewater. Biochemical method is usually used to remove biodegradable dissolved organic pollutants and part of colloidal pollutants to reduce BOD and part of COD in wastewater. After secondary treatment, about 90% biodegradable organic matter, 90% ~ 95% solid suspended matter and 80% ~ 95% BOD can be removed. Chemical coagulation sedimentation can also be used for treatment.
C. Three-level governance (also called deep governance). The sewage after secondary treatment is treated by physical and chemical technology to remove soluble heavy metal inorganic matter, non-degradable organic matter, various viruses, bacteria, phosphorus, nitrogen and so on. , and finally meet certain water quality requirements or use standards.
The degree of wastewater treatment depends on the export and utilization of treated water. If public sewers and irrigation are included, most of the wastewater only focuses on primary treatment. Discharged into the water body, the degree of treatment should be determined according to the water quality requirements of the receiving water body, taking into account the short-term and long-term situation, and implemented by stages. For some wastewater with simple components, a single unit process can often be used to achieve the goal, and there is no need to divide it into primary, secondary and tertiary treatment. Only when the composition is complex, or the composition is simple but the concentration is high, which requires high treatment, can a variety of treatment technologies be combined.
The treatment of mine wastewater must be based on wastewater control. First, take effective measures to reduce the amount of water entering the mine through various channels and control the spread of wastewater. In addition, the production process should be improved to reduce and eliminate the occurrence of pollution sources.
(4) Utilization of mine wastewater.
A. Recycle water, so that the wastewater can be reused for many times in a certain production process or a continuous water supply system is adopted to realize multi-purpose of one water, which can not only reduce wastewater discharge, but also reduce pollutant discharge concentration and save water.
B Wastewater contains some useful minerals, raw materials, semi-finished products and even finished products that enter the water body, and energy substances. Necessary measures can be taken to recover these substances and turn harm into benefit.
C wastewater treated by appropriate methods, but the treatment level can be used for drinking, irrigation or other industrial and domestic water, and the treatment method and treatment level should be determined according to its use.