Room and pillar mining pdf

Coal will continue to provide a major portion of energy requirements in the United States for at least the next several decades. It is imperative that accurate information describing the amount, location, and quality of the coal resources and reserves be available to fulfill energy needs.

It is also important that the United States extract its coal resources efficiently, safely, and in an environmentally responsible manner. A renewed focus on federal support for coal-related research, coordinated across agencies and with the active participation of the states and industrial sector, is a critical element for each of these requirements. Coal focuses on the research and development needs and priorities in the areas of coal resource and reserve assessments, coal mining and processing, transportation of coal and coal products, and coal utilization.

This report summarizes the results from the subsidence research study completed by the U. You will learn more about this if you take a rock mechanics course.

I want to talk about a few more terms. The openings driven between rooms are known as crosscuts. Recall also, that the point at which the material is being freed from the deposit is known as the face.

In the sketch, you can see five faces. The continuous miner is mining at one face, and a roof bolter is bolting at another face. Alright, there are just a few more terms, and then we fill in some additional detail for the method itself. The sequence of rooms in the direction of mining is known as an entry in a coal mine. They take on the appearance of well-laid-out streets in a city. Indeed, you can stand in an entry and see for quite a distance. What about the sequence of crosscuts?

What special name do we assign to that? The reason for that will become clearer within this lesson. The collection of rooms and pillars shown in this figure form a panel. In this case we have a five-entry panel. Three-entry panels are common, as are four and five.

There are additional details of note on the plan view. Notice that we are no longer representing the entries and cross cuts the same way. That makes it easier and faster to draw these diagrams.

As you look at this figure, you will see some of your newly acquired concepts, including Panels, Sections, Intakes, Returns, and Stoppings. There are also three new terms: overcasts, mains, and submains.

Overcasts are yet another type of ventilation control joining curtains and stoppings as controls to route ventilating air. Specifically, overcasts are used to route on type of air over tip of another. The overcast allows us to route, for example, intake air over top of a return aircourse without mixing the two airstreams. To satisfy your own curiosity, go ahead and trace the airflows in the part of the mine represented in the figure.

Now, on to the two other terms that I really wanted to highlight in this figure: the mains and submains. These are common terms in every coal mine and in some industrial mineral mines, e. These words are simply designating their importance in the overall mine plan. The mains serve as the primary means of distributing utilities throughout the mine as well as being the location for the primary transportation and materials handling routes.

The submains branch off of the mains to provide these same services to a group of panels, and the panels of course are the location for the active production sections. These word, mains and submains, and sometimes panels, are used as adjectives as well as nouns. The major aircourses supply air for the mine are known as the main intakes and main returns, for example. It is no coincidence that the mains have more entries than the submains, which usually have more entries than the panels.

Mains with seven to eleven entries are common. Often, three or four parallel entries are required to serve as intakes in larger mines, with two or three parallel returns, and another two isolated entries for material handling -- one being a belt entry and the other a track rail entry.

We now have a basic understanding of the layout for room and pillar mines, and we know the key terms that are used to describe them. Please see hharraz yahoo. Room and Pillar method: Prof. The pillars may or may not be removed after the removal of the ore.

This allows for greater recovery as less ore is left behind in pillars. Figure from Hartman and Mutmansky, Note the control of ventilation, i. Figure shows Room and Pillar is designed for mining flat, bedded deposits of limited thickness. Figures from Hartman and Mutmansky, Front benching Vertical benching Benching of thicker parts of orebody 7. Practical importance of the Room and pillars method: Method widely used in coal mines and non- carbon worldwide.

It is the mining method used in underground coal mining in southern Brazil. Harraz Presentation Room and Pillar method 7 8. Harraz Presentation Room and Pillar method 8 9. Harraz Presentation Room and Pillar method 9 From: Underground Min. Methods: Eng. Fundamentals and International Case Studies, , W.

Compare coal and non-coal in USA! Harraz Presentation Room and Pillar method 10 Harraz Presentation Room and Pillar method 11 Harraz Presentation Room and Pillar method 12 Harraz Presentation Room and Pillar method 13 Harraz Presentation Room and Pillar method 14 The stopes, the floor plan is maintained, allowing the transit of vehicles on tires.

Ore bodies are mined large vertical dimension in horizontal slices, starting at the top and ending with the floor dismount on countertops. Harraz Presentation Room and Pillar method 15 Harraz Presentation Room and Pillar method 16 Harraz Presentation Room and Pillar method 17 A special orientation of transit and stopes galleries creates areas with horizontal floor, allowing the use of equipment on tires.

The mining progresses from top to bottom in mining panels. Harraz Presentation Room and Pillar method 18 Have large vertical dimension, and filling the mined space suffers backfilling. The filler maintains the stable rock minimizes columns and serves as a working platform for the next slice. Harraz Presentation Room and Pillar method 19 Harraz Presentation Room and Pillar method 20 Main axis Mining panel Galleries return air contaminated Prof.

Harraz Presentation Room and Pillar method 21 Harraz Presentation Room and Pillar method 22 Harraz Presentation Room and Pillar method 23 Harraz Presentation Room and Pillar method 24 The overlying layer extracts the coal must be self-sustaining condition or be likely anchor there are several types of anchoring screws ceiling, with different principles of operation - see Appendix A.

Harraz Presentation Room and Pillar method 25 Bullock; cap. Harraz Presentation Room and Pillar method 26 Recovery of extraction: portion of reserves mined in relation to the total reserves. Comparative Example Retrieval. Harraz Presentation Room and Pillar method 27 Harraz Presentation Room and Pillar method 28 Harraz Presentation Room and Pillar method 29 C Mining with or without recovery of pillars: most common ways of mining Harraz Presentation Room and Pillar method 30 Recovery strategies pillars : Prof.

Harraz Presentation Room and Pillar method 31 Harraz Presentation Room and Pillar method 32 Equipment to aid in the recovery of pillars: Prof. Harraz Presentation Room and Pillar method 33 Harraz Presentation Room and Pillar method 34 Mining with pillar recovery : Prof.