nickel ore deposits

Do exploration on nickel ore deposits for mining and geological purposes.

Nickel

Notice

Introduction

Pure Nickel is a hard, silvery-white metal, the characteristics that made it very desirable, called for the combination with other metals, alloys, blends form. Some of the metals, may be alloyed with nickel, iron, copper, chromium and zinc. These alloys are used. In manufacture of metal coins and jewelry and in industry for the manufacture of products such as valves and heat exchanger Most nickel is used to make stainless steel. There are also compounds which consist of nickel with many other elements, including chlorine, sulfur and oxygen. Many of these nickel compounds are water soluble (dissolve fairly easily in water) and have a characteristic green color. Nickel and its compounds have no characteristic odor or taste. Nickel compounds are used for nickel to make color ceramics, some batteries, and as substances as catalysts, is known that to increase the rate of chemical reactions.

Nickel combined with other elements occurs naturally in the earth's crust. It is found in all soils, but is also emitted by volcanoes. Nickel is the 24th most abundant element. Into the environment, it is combined in the first place with oxygen or sulfur found as oxides or sulfides. Nickel is found in meteorites, on the ocean floor in pieces of minerals called sea floor nodules. The core consists of 6% nickel. Nickel is in the shared atmosphere during nickel mining and industries to use or nickel, nickel alloys or nickel compounds. These industries could also discharge nickel in wastewater. Nickel is also released into the atmosphere by burning oil-fired power plants, coal-fired power plants, waste incinerators and.

There is no recovery of nickel in the United States. A large part of our nickel used in industry comes from recycled nickel alloys or imported mainly from Canada and Russia.

Environmental Fate and Transport

Nickel can be used to the environment from the shelves of large ovens to be released alloys or from power plants and incinerators trash. The nickel that comes out of the stack of power plants attaches small dust particles that settle to the ground or be taken from the air in rain or snow. Normally it takes many days for nickel are removed from the air. If the nickel is connected to very small particles, there may be more than a month to settle out of the air. Nickel can also be released in industrial wastewater. An amount of nickel released into the environment ends up in the soil or sediment, where it attaches to the particles contained urgently, iron or manganese. Under acidic conditions, nickel is more mobile can seep into the soil and groundwater do not seem in. nickel concentrate in fish. Studies show that some plants can absorb and accumulate nickel. However, it has been shown that nickel does not accumulate in living small animals on land that has been treated with nickel-containing sludges.

Exposure pathways

Nickel normally occurs in very small amounts in the environment, the need so much sensitive methods to detect nickel in most environmental samples. Food is the major source of exposure to nickel. You may also be exposed to nickel by breathing air, drinking or smoking tobacco with nickel. Skin contact with soil, water bath or shower, or metals containing nickel, as well as metals with nickel can result in the exposure. Stainless steel and nickel-containing coins. Some jewelry plated with nickel or nickel alloys. Patients exposed to nickel in artificial body parts are made of nickel-containing alloys. Exposure of an unborn child to nickel. Through the transfer of nickel from the mother's blood to the fetus blood Likewise, infants are exposed to nickel through the transfer of nickel from mother to breast milk. However, the concentration of nickel in the mother's milk is either similar to or lower than the concentration of nickel in infant formulas, and cow's milk.

We often do not know the exact form of nickel, we are exposed, even on the most hazardous landfills. Much of the nickel found in the air, attached to soil, sediment and rock so much dust and dirt particles or embedded in minerals, it is not easily absorbed by plants and animals and therefore can not easily affect your health. In water and waste water can consist of either nickel dissolved in water or suspended in water.

Nickel in the air to small particles attached. Over a 6-year period (1977-1982) in the United States, Average nickel concentrations in cities and in the country ranged from 7 to 12 nanograms per cubic meter (ng / m, 1 ng / m³ equals 1 billionth of a gram in a cubic meter of air). More recently, EPA estimates that the average nickel concentration in the air in the United States dropped to 2.2 ng / m, based on information obtained on air quality from 1996.

The concentration of nickel in the water of rivers and lakes is very low,. The average concentration is usually less than 10 parts of nickel in a billion parts of water (ppb) The level of nickel in the water is often so low that we can not measure unless we use very sensitive instruments. The average concentration of nickel in the drinking water in the United States is between 2 and 4.3 ppb. However, you may be exposed to higher than average levels of nickel in drinking water if you live in the area, industries that process or use nickel. The highest levels of nickel in drinking water, about 72 ppb, near areas found a large natural nickel deposits, where nickel is mined and refined.

The soil contains usually between 4 and 80 parts of nickel in one million parts of soil (ppm, 1 ppm = 1000 ppb). The highest concentrations of the soil (up to 9,000 ppm) extract found near industries that nickel from ore. Results in high concentrations of nickel dust will act as that. In the air from stacks during processing and sits down on the floor You can be exposed to nickel in soils by skin contact. Children can also be exposed to nickel by eating earth.

Food contains nickel and is the major source of nickel exposure for the general population. They eat about 170 micrograms (ug, 1 pg = 1 millionth of a gram) of nickel in your diet every day. Foods naturally high in nickel include chocolate, soybeans, nuts and oatmeal. Our daily intake of nickel from drinking water is ug only about 2. We inhale 0.1 to 1 ug nickel / day, with the exception of nickel in tobacco smoke. We are on nickel, exposed when we deal with coins and touch other metals nickel.

You may be exposed to higher nickel if you nickel in industries that use or process of work. You can also to nickel by inhalation of dust or smoke (from welding) or exposed to skin contact with nickel-containing metal dust or solutions containing dissolved nickel compounds. A national survey conducted from 1980 to 1983 estimated that 727,240 workers are potentially exposed to nickel metal, nickel or nickel compounds.

Metabolism

Nickel can enter your body when you nickel with air when you breathe, eat or drink water that contains nickel, and if your skin comes into contact with nickel. When you breathe air containing nickel, the amount of nickel reaches you inhale that your lungs and enters your blood depends on the size of the nickel particles. If the particles are large, they remain in the nose. If the particles are small, they can delve deep into your lungs. Nickel is absorbed from your lungs into the body, when the nickel particles are easily soluble in water. If the particles do not readily dissolve in water, the nickel may remain in the lungs for a long time. Some of these particles can leave the lungs with mucus nickel you. Spit or Swallow Nickel is in your body penetrate your stomach and intestines, if you drink water, nickel, as if you are eating foods that. The same amount of nickel A small amount of nickel may occur contact your blood from the skin. After nickel in your body is, it can go to all the organs, but it is all about the kidneys. The nickel that gets into your bloodstream leaves in the urine. Is eaten by nickel, it leaves most rapidly in the feces, and the small amount that gets into your blood in the urine leaves.

Health Effects

The most common adverse health effect of nickel in humans is an allergic reaction. Approximately 10-20% of the population is sensitive to nickel. A person may thus sensitive nickel as jewelery or other goods, the nickel are in direct contact and prolonged contact with skin. Wearing jewelry containing nickel in the ears or other body parts that may have been newly pierced to sensitize a person nickel. However, not all jewelry is nickel-containing releases enough of the nickel ions to sensitize a person. Once a person is sensitized to nickel, further contact with the metal probably a chemical reaction. The most common reaction is to contact a skin rash at the site. In some sensitized people, dermatitis (a type of skin rash) in an area of ​​skin that develop from the site of contact. For example, hand eczema (another type of skin rash) is widespread among people sensitized nickel. Some workers may be exposed to nickel by inhalation sensitized and have asthma attacks, but this is rare. People who are sensitive to nickel is nickel, the reactions, if prolonged contact with skin. Some sensitized people react when they eat nickel in food or water or breathe dust nickel. More women than men are sensitive to nickel. This difference between men and women is thought. A result of the greater burden on women by the nickel-metal jewelry and other items

Who is not sensitive to nickel must eat very large amounts of nickel to suffer adverse health effects. Workers who had accidentally drank bright green water with 250 ppm of nickel from a contaminated wells suffered stomach pains and negative effects in their blood (increased red blood cell) and kidneys (increased protein in the urine). This concentration of nickel is more than 100,000 times greater than the amount normally found in drinking water.

The most serious adverse health effects from exposure to nickel, such as chronic bronchitis, reduced lung function and cancer of the lung and nasal sinuses have occurred in people who have inhaled dust containing certain nickel compounds while working in refineries or nickel nickel-processing plants. The content of nickel in these workplaces were much higher than usual (in the background) in the environment. Lung and sinus cancers occurred in workers who resolve more than 10 mg nickel / m³ exposed as nickel compounds that were difficult (such as nickel subsulfide). Exposure to high nickel compounds, readily soluble in water (soluble) can also result in cancer when nickel compounds that are difficult to solve (less soluble) present, or if other chemicals that can cause cancer are present. The concentrations of the soluble and less soluble nickel compounds that were found cancers produce 100,000 to 1 million were times greater than the usual level of nickel in the air in the United States. The U.S. Department of Health and Human Services (DHHS) has determined that nickel metal on reasonably carcinogenicity and nickel compounds are known human carcinogens. The International Agency for Research on Cancer (IARC) has determined that some nickel compounds are carcinogenic to humans and that metallic nickel may be carcinogenic to humans. The EPA has determined that nickel refinery dust and nickel subsulfide are human carcinogens. These classifications have been cancer. Based on studies of nickel workers and laboratory animals

Lung inflammation and damage to the nasal cavity nickel compounds observed in exposed animals. At high concentrations, the lung damage is severe enough to impair lung function. Long-term exposure to a lower level of a nickel compound, dissolves readily in water produce cancer in animals. Lung cancer develops in rats for a long time to nickel compounds that do not dissolve readily in water.

Oral exposure of humans high levels of soluble nickel compounds on the environment is extremely unlikely. Because people rarely exposed to high levels of nickel in water or food, much of our knowledge about the harmful effects of nickel is based on animal studies. Eating or drinking levels of nickel much higher than the amount normally found in food and water have been reported to produce pulmonary disease in dogs and rats, and the stomach, blood, liver, kidneys and immune system of rats and mice, as well as their reproduction and development .

Effects on Children

It is likely that the health effects in children exposed to nickel is seen similarly the effects observed in adults. We do not know whether children differ from adults in their susceptibility to nickel. Human trials investigated whether nickel can not harm the fetus developing countries are inconclusive. Animal studies, the deaths have increased in neonates and decreases weight found in neonates after ingesting nickel.

These doses are 1,000 times higher than levels found in drinking water in general. It is likely that nickel from the mother, a child can be transferred into breast milk and cross the placenta. The nickel content in breast milk are probably similar to the levels in cow's milk or soy milk-based infant formula.

Reducing exposure

People can by wearing jewelry nickel that contains nickel exposure. In some people, wearing jewelry that contains nickel, produces irritation. Avoid jewelry with nickel is eliminated risk of exposure to this source of this metal. Other sources of nickel exposure through the food you eat and drink water. But the amount of nickel in food and drinking water are too low to be of concern.

Medical Tests

The measurements of the amount of nickel in your blood, feces and urine. Estimating your exposure to nickel Nickel in the urine of workers who were exposed to nickel compounds that dissolve easily in water (soluble) and are exposed to the urine of workers compounds difficult to solve (less soluble). This means that it is easier to tell if you were exposed to soluble nickel compounds than less soluble compounds. The nickel-measurements do not accurately predict the potential health effects from exposure to nickel.

U.S. government recommendations

The federal government develops regulations and recommendations to protect public health. Regulations can be enforced by law. The EPA, the Occupational Safety and Health Administration (OSHA), and the Food and Drug Administration (FDA) are some federal agencies develop,. Regulations for toxic substances Recommendations provide valuable guidelines to protect public health but can not be enforced by law. The Agency for Toxic Substances and Disease Registry (ATSDR) and the National Institute for Occupational Safety and Health (NIOSH) are two organizations that develop recommendations for the federal toxic substances.

Regulations and recommendations can "not-to-exceed" levels, that is expressed as a toxic substance in air, water, soil, or food that is no longer than a critical value, usually at levels that affect animals base, they are then adjusted to levels that. contribution to the protection of human Sometimes this can not be distinguished between the levels exceed federal organizations used because different exposure times (an 8-hour workday or a 24-hour day), different animal studies, or other factors.

Recommendations and regulations are also periodically updated as more information becomes available. For the latest information, check with the federal agency or organization that provides it. Some regulations and recommendations for nickel include the following:

OSHA has. An enforceable limit of 1.0 mg nickel / m for metallic nickel and nickel compounds in the air Set workspace for workers during an 8-hour shift over a 40-hour protection week EPA recommends that drinking water levels for nickel should not exceed 0.1 mg per liter.

No comments:

Post a Comment

Note: Only a member of this blog may post a comment.