Mining and quarrying extract a variety of valuable materials from the ground, including coal, metals, and stone. These materials are widely used in the construction and manufacturing industries, whereas precious stones have long been used for adornment and decoration. Mining and quarrying entail locating potential extraction sites, extracting the required material from the ground, and then processing it with heat or chemicals to extract the metal or other substance of interest. All of these operations may necessitate the use of large amounts of water.
Mining and quarrying can be extremely damaging to the environment. They have a direct impact on the environment by leaving pits and heaps of waste. Sulfur dioxide and other pollutants from the extraction processes can also contaminate the air and water, putting wildlife and local populations at risk. More careful use of natural resources, including recycling, as well as post-mining and quarrying restoration efforts, can help limit these environmental impacts.
Background History and Scientific Principles
People have always mined useful materials from the earth. Knowledge of how to obtain these materials was central to the Stone, Bronze, and Iron Ages. Archaeological studies have revealed evidence of copper mining in Africa around 6,000 years ago, as well as in ancient Egypt and North America a little later. Meanwhile, the Romans invented numerous mining techniques to improve the efficiency of the process. Almost every manufactured item today contains material that was mined or quarried.
Mining is the extraction of an economically valuable material from the ground. Mined materials include ores, coal, evaporites, and precious stones and metals. Quarrying is the cutting or digging of stone and related materials from an excavation site or pit, leaving a large hole in the ground behind. An ore is a deposit that contains a commercially viable amount of a mineral, which is a crystalline inorganic compound that typically contains a metal. It is the metal itself that is valuable. The main mineral groups mined are oxides, sulfides, and silicates. Aluminum, manganese, copper, chromium, and nickel are the most important metals economically.
Evaporites are materials that are deposited in the ground as a result of chemical solution evaporation. They include rock salt, which is used in cooking and water softening, and gypsum, which is used to make plasterboard. Diamonds, precious metals, and gemstones are always in high demand for decorative purposes, including jewelry. Meanwhile, large quantities of gravel, clay, sand, and limestone are quarried for use in building materials such as concrete, cement, and glass. Crushed stone from quarries is widely used in road construction. A mile of highway could necessitate nearly a quarter-million tons of crushed stone. Sulfur deposits are primarily mined for the production of sulfuric acid.
Mining and quarrying are divided into three stages. First, there is exploration and assessment to determine whether a resource is valuable enough to exploit. This could necessitate some drilling into the ground. The substance is then extracted using the most appropriate technique for its location. This is frequently determined by the depth of the resource beneath the surface. Open pit and shallow strip mining are common methods for extracting resources up to 600 feet (180 meters) below ground. The mining process removes the source as well as the rock and soil on top of it, known as overburden. Close by, the overburden is piled into a so-called spoil heap. Underground mining, which can reach depths of up to 8,000 feet, will be used to extract deeper resources (2,440 m). Above this point, temperatures rise to the point where mining is no longer feasible. Generally, rock removed to construct mining tunnels is added to the spoil heap. Finally, the ore or other resource must be processed in order to extract the desired metal or material. Typically, this entails some sort of heat or chemical treatment. Smelting, for example, is a common type of processing that involves roasting an ore to release the metal it contains.
Issues and Repercussions
Mining and quarrying have frequently been chastised for their social and environmental consequences. Because of improved technology and safety measures, the industry claims far fewer lives in modern times. Mining, on the other hand, was a difficult and dangerous occupation. Valuable materials such as gold and diamonds have frequently been used to fund corrupt regimes, crime, and terrorism, while inhuman labor conditions have frequently been used in their extraction.
Mining and quarrying have a variety of environmental consequences. While the extractions are taking place, the landscape is visibly altered, and habitat loss is possible. The mining operations themselves, as well as the accompanying spoil heaps, cause a drastic change in the location, resulting in direct habitat destruction and the blocking or burying of nearby bodies of water. Mining frequently has an impact on local hydrology, causing changes in water flow and quality. Large mining pits frequently fill with groundwater, which then contaminates the environment.
Mining operations in the Marikina River Basin should not be blamed for the massive flooding that engulfed some parts of Marikina and Rizal province during the onslaught of Typhoon Ulysses, the country's deadliest and most destructive typhoon in 2020.
The Mines and Geosciences Bureau (MGB) recently lifted the temporary suspension of several quarries and crushing plants in Rizal province, indicating this. "Flooding, erosion, and siltation will occur in the Marikina River Basin with or without mining operations," MGB stated. "The quarrying operations in Rizal account for only a small portion of the land disturbance." "These operations have only a minor impact on the flooding and siltation of the Marikina River," it added.
The investigation was sparked by the flooding caused by Typhoon Ulysses on November 12, 2020, which submerged low-lying areas in Marikina City and the municipalities of San Mateo and Rodriguez, Rizal, particularly those along the Marikina-Wawa River.
At the time, Governor Rebecca Ynares specifically requested that the DENR suspend quarry operators' mining permits in the province pending the completion of an extensive investigation into whether quarrying contributed to the flooding in the province.
Three months later, the DENR Composite Team concluded, among other things, that the flooding on November 12, 2020 in Marikina City and surrounding areas was primarily caused by Typhoon Ulysses' massive amount of rainfall.
The DENR Composite Team, for its part, stated that it has asked the aforementioned companies to first comply with certain conditions before they can resume operations, including the construction of drainage systems with appropriate multiple silt traps/sumps and gradients to ensure the efficacy of the drainage system to be installed.
The DENR also ordered the companies to build a settling pond or catchment basin and to de-silt the creek/tributary affected by the siltation caused by their entire operation.
MGB stated that the suspensions of quarrying and mineral processing operations were lifted only after compliance with these conditions.
