User talk:Mervyn Emrys/

Recent Coal mining edits
Thank you for your recent edits to the article coal mining, it is great to have more people who are able to expand on articles with the Mining WikiProject. One concern that I have is in the section listed below.


 * Coal is mined only where technically feasible and economically justifiable. Evaluation of technical and economic feasibility of a potential mine requires consideration of many factors: regional geologic conditions; overburden (e.g., rock and soil) characteristics; coal seam continuity, thickness, structure, quality, and depth; strength of materials above and below the seam for roof and floor conditions; topography (especially altitude and slope); climate; land ownership as it affects the availability of land for mining and access; surface drainage patterns; ground water conditions; availability of labor and materials; coal purchaser requirements in terms of tonnage, quality, and destination; and capital investment requirements.

That is sort of a motherhood statement for all mining, regardless of the material, and probably does not belong in the extraction methods, perhaps a summerized version in an economics section (with coal specific economic needs). That paragraph should be generalized (i.e. minerals are only mined where technically feasible and economically justifiable...) and entered into the article mineral economics Should be in the economics section in the coal mining article...Thoughts???--Kelapstick (talk) 18:13, 30 October 2008 (UTC)


 * I don't think so. Assessment of technical and economic feasiblilty is an integral part of the mining of coal, and the method used to mine often turns on it. Strip ratios (tons or yards of overburden to coal) are largely determined by the current price of coal, and that may determine choice between area or underground mining technique. It is not a "motherhood statement for all mining" because most minerals do not occur in seams, but are dispersed in an ore body (e.g., uranium, lead, nickel, iron)or occur in fine "veins"(e.g., sometimes gold, silver). Coal is a relatively "pure" mineral in this respect, and often occurs in several seams separated by rock or baked mud (I've seen as many as 18 in Indonesia, and 10 in the Western U.S.). Other "pure" minerals like phosphates and gypsum occur in even larger sedimentary "beds" that are difficult to characterize as seams. So several of the factors described for coal would not apply to other minerals. The statement is therefor limited to coal. Mervyn Emrys (talk) 20:19, 30 October 2008 (UTC)


 * Assessment of technical and economic feasibility is an integral part of copper, zinc, gold (etc. etc.) mining. That entire paragraph can be re-written for copper (or any other type of mining) by replacing 5 words (2 of them being coal)


 * Copper is mined only where technically feasible and economically justifiable. Evaluation of technical and economic feasibility of a potential mine requires consideration of many factors: regional geologic conditions; overburden (e.g., rock and soil) characteristics; ore body continuity, thickness, structure, quality (grade), and depth; strength of materials above and below the ore body for roof and floor conditions; topography (especially altitude and slope); climate; land ownership as it affects the availability of land for mining and access; surface drainage patterns; ground water conditions; availability of labor and materials; copper purchaser requirements in terms of tonnage, quality, and destination; and capital investment requirements.


 * All I am saying is that that portion is be better suited in mineral economics as it covers any type of resource extraction.


 * My recomended change to that paragraph would be (with the economics and technical feasibility portion move to the mineral economics article):


 * Methods of extraction


 * The extraction method of a coal seam depends on its depth and quality. There are also geological and environmental factors of the area being mined.  As with all types of mining ,coal is mined only where technically feasible and economically justified.


 * The two basic methods of mining a coal reserve are surface mining and underground mining. Seams relatively close to the surface (depths less than approximately 180 feet), are usually surface mined. Coal reserves that occur at depths of 180 to 300 feet are usually mined from underground access however in some cases surface mining techniques can be used if the seam is thick enough to warrant it (i.e. 60-90 feet). Coal seams occurring below 300 feet are usually mined using underground techniques.--Kelapstick (talk) 21:01, 30 October 2008 (UTC)

I disagree. It doesn't work. Yes, there are technical and economic assessments for copper and other minerals but the factors are different than for coal seams due to the differences in nature of the mineral deposits. Copper does not occur in seams like coal does. Except for very small artisanal mines, copper ore bodies are virtually always surface mined today, so there are no "roof conditions" for copper. Coal quality is not a simple matter of "grade" but a composite of several factors including moisture content, ash, VOC (volatile organic compounds) sulfur content, heat content (Btu), and several mineral impurities including lead, mercury, pyrites, carbonaceous shale and a few others. And there are severl types of coal having different physical characteristics, including lignite, anthracite, bituminous, sub-bituminous... It's NOT just economics. Some are technical parameters, some of which affect cost and others affect only technical choices of mining techniques. One cannot use a bucketwheel excavator with anthracite... I think you are trying to fit a square peg into a round hole here, and it won't fit. If you try to force it, you will distort the meaning tortuously or break something. Mervyn Emrys (talk) 01:15, 31 October 2008 (UTC)