Introduction

Coal refers to a fuel fossil that is obtained from plant materials that were buried and decomposed millions of years ago on the earth’s surface. The Powder River basin is found in Montana and it stretches from Wyoming’s Bighorn Mountains to the yellow river found in Montana. This area is a landscape with grass that covers its plains, hills, flood plains, swamps and streambeds. It is the largest coal producing region in the united state of America for years.

Geological history of coal formation in Wyoming State U.S.A

The Powder River basin is rich in phanerozic rocks that are thick in nature. The thick parts of these rocks are the basic foundation of coal formation since they are made of rocks known as cretaceous. These rocks are as a result of marine shells and sandstones that were deposited from the sea. Coal beds are said to have began forming 60 million years ago the time when the land started emerging from shallow sea. The black hills and Hartville uplifts on its southeast location formed the present day Powder River. The coal bed started to form during the periods when the climatic conditions were still subtropical about 2500-3000 mm of rainfall annually (Knibbs, 34-41).

Initially, the floor of the basin was widely covered with lakes and swamps therefore, the swamps organic materials began to build up into the peat bogs rather than being deposited to the sea. The layers on the peat bogs were enclosed with sediments from the nearby mountains. As time went by, the earth’s climatic conditions started to change becoming drier and cooler than the previous wet and warm climate. The existing basin was filled up with sediments and as a result, the peats were buried deep thousands of feat under the ground. The remaining layers of the peat bogs started to compress hence forming coal. Millions of years ago, the sediments gnarled away as coal seams were left near the surface (Dysart & Clawson 36-40).
Coal stripping in Wyoming U.S.A

The process of coal extraction depends on the depth of the seams either on the surface or underground. Coal mined from both surface and underground mines are cleaned in coal preparation plant. For surface mining, the coal seams are near the surface therefore it is economical to mine it using open strip method. There is use of explosives to break down the surface to be mined. Then coal is extracted using equipment known as dragline or a truck. This process exposes the coal seam that is drilled and mined in number of strips. The mined coal is parked on haulers for transportation (Wesley, 45-53).
Coal can also be mined using a method known as room and pillar that contains the deposits mined by stripping off rooms of coal seams. Then the pillar of coal is left behind in order to maintain the roof; the pillar comprise of three quarters of the coal seams that are extracted at advanced stage.

Underground mining on the other side is applied to situations when the coal to be mined is buried deep in the surface. In order to extract coal from such underground mines, the miners use elevators down the mine where machines are used to strip out the coal.
In addition, advancement in technology has made mining easy and less harmful than it was some years ago. Coal mining companies have adapted the use of new instrument panels, huge trucks equipped end loaders and computer console. The underground walls of the mines are painted white and covered with coating of lime whose function is to prevent coal dust. The mines are also fitted with systems that ensure fresh air is constantly supplied and flows sufficiently this process is aided by big ventilation fans on the surface. However, personal protective equipments are used. For instance, the coal miners usually wore hard hats, steel toed boots and hearing protection gear. Furthermore, purifying systems and high intensity lamps are also used in the mining process (Ulrich, 76-82).