A regular room and pillar method is used in a hard rock leadzinc mine. The ore horizon
Question:
A regular room and pillar method is used in a hard rock lead–zinc mine. The ore horizon is at a depth of 300 m where the overburden averages 25kN/ms. Laboratory tests on core samples (L/D = 2) show that the ore has an unconfined compressive strength of 86 MPa and a tensile strength of 7 MPa. Find an algebraic expression for the maximum extraction ratio possible, if no size effect exists, then evaluate the expression for the given data.
Fantastic news! We've Found the answer you've been seeking!
Step by Step Answer:
Answer rating: 62% (8 reviews)
Given Room and pillar mine 300 m depth y25 kNm core LD 2 Co86 MPa To7 MP...View the full answer
Answered By
Aysha Ali
my name is ayesha ali. i have done my matriculation in science topics with a+ . then i got admission in the field of computer science and technology in punjab college, lahore. i have passed my final examination of college with a+ also. after that, i got admission in the biggest university of pakistan which is university of the punjab. i am studying business and information technology in my university. i always stand first in my class. i am very brilliant client. my experts always appreciate my work. my projects are very popular in my university because i always complete my work with extreme devotion. i have a great knowledge about all major science topics. science topics always remain my favorite topics. i am also a home expert. i teach many clients at my home ranging from pre-school level to university level. my clients always show excellent result. i am expert in writing essays, reports, speeches, researches and all type of projects. i also have a vast knowledge about business, marketing, cost accounting and finance. i am also expert in making presentations on powerpoint and microsoft word. if you need any sort of help in any topic, please dont hesitate to consult with me. i will provide you the best work at a very reasonable price. i am quality oriented and i have 5 year experience in the following field.
matriculation in science topics; inter in computer science; bachelors in business and information technology
_embed src=http://www.clocklink.com/clocks/0018-orange.swf?timezone=usa_albany& width=200 height=200 wmode=transparent type=application/x-shockwave-flash_
4.40+
11+ Reviews
14+ Question Solved
Related Book For
Question Posted:
Students also viewed these Geological Engineering questions
-
Laboratory tests on core from exploration drilling show that Co = 148.3 MPa, To = 10.55 MPa, E = 43.10GPa, G = 17.24GPa, = 22.78kN/m3, while premining stress measurements can be fit to the formulas...
-
Calculate the gauge pressure at a depth of 300 m in seawater.
-
Laboratory tests on core from exploration drilling show that Co = 21,500 psi, To = 1,530, E = 6.25(106) psi, G = 2.5(106) psi, = 144pcf, while premining stress measurements can be fit to the...
-
East Corp is a mature company and expects its sales and operating costs to be fixed (or unchanged) in perpetuity. It has sales of $524,000 and operating costs of $272,480. The firm has a tax rate of...
-
After filtering through the atmosphere, the Sun's radiation illuminates Earth's surface with an average intensity of 1.0 kW/m2. Assuming this radiation strikes the 15-m 45-m black, flat roof of a...
-
Explain how a mutagen can interfere with DNA replication to cause a mutation. Give two examples.
-
A thin layer of an incompressible fluid flows steadily over a horizontal smooth plate as shown in Fig. P7.55. The fluid surface is open to the atmosphere, and an obstruction having a square cross...
-
Heathrow issues $2,000,000 of 6%, 15-year bonds dated January 1, 2011, that pay interest semiannually on June 30 and December 31. The bonds are issued at a price of $1,728,224. Required 1. Prepare...
-
A person has just been appointed Immigration Czar, giving him absolute power over immigration status questions in the United States. For purposes of this exercise, U.S. immigration law is exactly...
-
Bug-Off Exterminators provides pest control services and sells extermination products manufactured by other companies. The following six-column table contains the company's unadjusted trial balance...
-
Suppose that entries and crosscuts are 30 ft wide and that pillars are square and 30 ft wide, as in Problem 6.17. Laboratory properties are the same as in Problem 6.15; depth and specific weight of...
-
With reference to Problem 19, if pillars are square and rooms (entries and crosscuts) are 9 m wide, what size of pillars is indicated when the pillar safety factor is 2?
-
(a) How large do we have to take so that 1/x2 (b) Taking r = 2 in Theorem 5, we have the statement Prove this directly using Definition 7. lim
-
For each nN let X, be a random variable such that 0Xn Xn+1 for any n N and define Ylim-00 Xn- Also, let Z = -1214, be a simple random where A..... Am are pairwise disjoint events, zj (0,00) and A, C...
-
You are walking down a straight path in a park and notice there is another person walking some distance ahead of you. The distance between the two of you remains the same, so you deduce that you are...
-
Link to the online article about finance One paragraph with a brief narrative of the article And another paragraph with your own thoughts regarding the article (for example, why it is interesting,...
-
The risk-free return on a government bond is 0.02. A risky asset is available with a return of 0.10 and a standard deviation of 0.04. a) Assume you are optimally willing to accept a standard...
-
OPERATING Income Margin = EBT / Sales Please do these calculations based on the income statement from years 2017-2022 please find financial statement for Bunge here...
-
Presented on page 865 is selected information related to the financial instruments of Dawson Company at December 31, 2015 (amounts in thousands). This is Dawson Companys first year of operations....
-
The vapor pressure of the liquid NH, is measured at different temperatures. The following vapor pressure data are obtained. Temperature, K P, mmHg 217.1 223.4 234.7 588.1 Calculate the enthalpy of...
-
On a hot summer day, 4.00 10 6 J of heat transfer into a parked car takes place, increasing its temperature from 35.0C to 45.0C. What is the increase in entropy of the car due to this heat transfer...
-
In many amplifier applications we are concerned not only with voltage gain, but also with power gain. Power gain = Ao =(power delivered to the load)/(power delivered by the input)Find the power gain...
-
Find the power absorbed by the 10-K ohms resistor in the circuit shown. 11 mA 10 k 2000
-
Find the power absorbed by the 12-K ohms resistor in the circuit shown. 12 k 6 mA
-
Assume that management wants wage concession from its counterpart labor union. Explain why this often leads to disputes. Suppose management gives up some of its future negotiating power by subjecting...
-
Why have you chosen this nursing Field of Specialization or Major? What influenced you in selecting your intended major of study and what goal(s) have you set for the future?
-
What are logical fallacies and how can they affect our decision-making?
Study smarter with the SolutionInn App