Cambridge Mock Interview For Class 9 To 12

How to create an outline for class 6

The total amount of gold mining in the world makes 2200 t. First place in the world on gold mining is won by the Republic of South Africa (522 t), the second – the USA (329 t). The oldest and deepest gold mine in the USA – Houmsteyk in Mountains Black Hills (Southern Dakot; gold mining is conducted over 100 years there. Modern methods of extraction (imanirovan do profitable extraction of gold of numerous poor and poor fields.

As gold is almost not subject to corrosion and is highly appreciated, it remains eternally. So far in the form of ingots, coins, jewelry and objects of art not less than 90% of the gold extracted for the historical period reached. As a result of annual world production of this metal its total quantity increases less than by 2%.

Education conditions. Oil-and-gas decantation basins are usually connected with certain geological structures. Practically all large deposits of oil are dated for crust sites which tested for a long time a progibaniye therefore there especially powerful sedimentary thicknesses collected.

About 2/3 world resources of silver are connected with polymetallic copper, lead and zinc ores. Silver is extracted generally in passing from a galenite (sulfide. Fields mainly vein. The largest producers of silver – Mexico (2323 t), Peru (1910 t), the USA (1550 t), Canada (1207 t) and Chile (1042 t).

To perspective, replacing natural mineral raw materials, ceramic and semiconductor materials belong. Metals, ceramic and polymeric materials are used as a matrix and the reinforcing components for consolidation of various composite materials. Plastics, or polymers – the material which is most widely used in the USA (it is more, than steel, copper and aluminum are together taken. As initial raw materials for receiving plastic products of petrochemical synthesis serve. However as raw materials instead of oil also coal can be used.

Have the greatest reserves of bauxites Guinea (42% world a stock, Australia (18,5%), Brazil (6,3%), Jamaica (4,7%), Cameroon (3,8%) and India (2,8%). On production scales (42,6 million t) first place is won by Australia.

The big part of oil fields is dispersed on six regions of the world and dated for inland territories and suburbs of continents: The Persian Gulf – North Africa; The Gulf of Mexico – the Caribbean Sea (including coastal areas of Mexico, the USA, Colombia, Venezuela and the lake of Trinid; islands of the Malay Archipelago and New Guinea; Western Siberia; northern Alaska; North Sea (mainly Norwegian and British sectors); Sakhalin Island with adjacent sites of the shelf.

Table salt is received from fields of rock salt and by evaporation of water of salty lakes and sea water. World resources of table salt are almost inexhaustible. Almost each country has or deposits of rock salt, or installations on evaporation of salty water. An enormous source of table salt – the World Ocean.

it is got more than in 100 countries. Her largest producer – the USA. Nearly a half of the extracted table salt is used in chemical industry, 1/4 is spent for prevention of frosting of highways. Besides, it is widely applied in the tanning and food industry and is important foodstuff of the person and animals.

About 64% of all nickel made in the world are used for receiving nickel steel, 16% of nickel are spent for electroplated coatings of steel, brass, copper and zinc; 9% – on superalloys for turbines, aviation fastenings, turbocompressors, etc. Nickel is applied when stamping coins.

– the most valuable and one of the most widespread non-ferrous metals. The largest consumer of copper – the electrotechnical industry. Copper is widely applied in automotive industry and construction, and also spent for production of brass, bronze and copper-nickel alloys.

Bauxites, main raw materials of the aluminum industry. Bauxites are recycled on alumina, and then from - aluminous fusion receive aluminum. Bauxites are widespread mainly in damp tropics and subtropics where processes of deep chemical aeration of rocks proceed.

The majority of types of mineral raw materials is presented by the ores consisting of minerals, i.e. inorganic substances of a natural origin. However some important types of minerals, in particular power raw materials, have an organic origin. They are attached to mineral raw materials conditionally.