Cut-off Grade Theory and Practice. Consider a block of ore that weighs 1 tonne and contains 3 grams of gold. At a gold price of US$1000 per ounce the …
Read MoreUsing the cut-off value – tonnage distribution for Mine A, it can be seen that a marginal break-even cut-off grade for the ore reserves estimate can have significant downside effect if there is ...
Read MoreThe Kamoa-Kakula Copper Project — a joint venture between Ivanhoe Mines (39.6%), Zijin Mining Group (39.6%), Crystal River Global Limited (0.8%) and the Government of the Democratic Republic of Congo (20%) — has been …
Read MoreThe cut-off grade of an ore is essentially the lowest grade of an ore that is worth mining. If the ore grade is less than the cut-off grade, then a mining company will not make money mining that ore. According to Fellows (2010), the cut-off grade of an ore is one of the main factors in determining the economics of the mine.
Read MoreScience. Earth Sciences. Earth Sciences questions and answers. Question 61 (1 point) How many pounds of 5% grade copper ore need to be mined to get 500 lbs of copper? 25 0 100 2500 0 10,000 Question 62 (1 point) Many closed mines exist throughout the United States (and other countries). If the cut-off grade drops for ores once extracted from ...
Read MoreThe average grade of copper ores in the 21st century is below 0.6 percent copper, with the proportion of ore minerals being less than 2 percent of the total volume of the ore rock.
Read MoreCutoff grade is defined as the grade that is normally used to discriminate between ore and waste within a given orebody. Although the definition of cutoff grade is very precise, the choice of a cutoff grade policy to be used …
Read MoreOptimum cut-off grade policy for open pit mining operations through net present value algorithm considering metal price and cost escalation. By Raul Cezar. Maximizing the net present value by applying an optimal cut-off grade for long-term planning of the copper open pits.
Read MoreYousuf Azimi. M. Osanloo. Determination of cut-off grade strategy is one of the most important stages of open pit mine planning and design. It is …
Read MoreThe vertical extent of ore is dependent upon the lower copper cutoff grade, which will vary with the price of copper and local mining costs. At Dos Pobres, Arizona, from the top of the orebody to the 0.2 percent copper cutoff at its deepest points is approximately 1–1.2 km (Langton and Williams, 1982).
Read MoreStill, it is better to have a higher than lower cut-off grade, as a higher cut-off grade will extend the life of the mine, and if there is a business case, capacity can be added. So using the example above, we can assume that 3.5g/t AuEq is the calculated minimum ore grade necessary to operate productively given all the geologic, environmental ...
Read MoreAn example for a polymetallic deposit can be seen below. Assume a selling price of $2,500, $2,400 and $6,500 per tonne of zinc, lead and copper, respectively. For this example, the selling cost has been chosen to be 5% of the …
Read MoreCalculation of Cut-off Grade Using Net Smelter Return (NSR) Net Smelter Return is a measure of the value of ore and is defined as the proceeds from the sale of mineral products, after deducting transportation and treatment …
Read MoreCut-off Grade Theory and Practice. Consider a block of ore that weighs 1 tonne and contains 3 grams of gold. At a gold price of US$1000 per ounce the value of the gold in the block of ore is just under $96 ($1000/31 X 3 or $1000 …
Read MoreA cut-off grade of 1.2% copper is used to estimate Ore Reserve in the higher-grade lodes 102 and 108. A cutoff grade of 0.9% copper is used for the lower grade 101 and 105 lodes that are to be mined in retreat at end of mine life. The Murrawombie deposit has separate Ore Reserve estimates for underground mining; and open pit mining.
Read MoreCutoff grade is defined as the grade that is normally used to discriminate between ore and waste within a given orebody. Although the …
Read MoreCut-Off Grade (percentage per tonne) $ 33. $ 3. ($ 33 / $ 3 =) 11 pounds / tonne. ( (11 / 22) x 1% =) 0.50 percentage /tonne. Note: When the cost price per tonne …
Read MoreSuch increases in scale may be accompanied by changes in cut-off grade, the boundary between ore that is processed and material that is sent to waste dumps. Technological progress and rising productivity tend to allow the extraction of ever leaner ores, but rising costs of all types tend in the other direction.
Read MoreMineral Resources for the Santo Domingo Sur, Iris, Iris Norte, and Estrellita deposits are reported using a cut-off grade of 0.125% CuEq. CuEq grades are calculated using average long-term prices of US$3.50/lb Cu, US$1,300/oz Au, and US$99/dmt Fe conc.
Read MoreOptimum cut-off grades determination in mining life affects production planning and ultimate pit limit and it is also important from social, economical and environmental aspects. Calculation of optimum cut-off grades has been less considered for
Read MoreIn the mining industry, cut-off grade is arguably the single most important policy and operating parameter. The cut-off grade value directly …
Read MoreThe copper Mineral Resources are reported within geological volumes based on a nominal NSR copper cut-off value of EUR 32.85/t (grade equivalent to 1.0% copper), and the zinc Mineral Resources are reported within geological volumes based on a nominal NSR zinc cut-off value of EUR 30.55/t (grade equivalent to 4.5% zinc).
Read MoreIncremental cut-off grades can be calculated by converting the incremental downstream mining and processing costs at the decision point into a cut-off grade by dividing the cost by the metal price ...
Read MoreDaniel Kržanović, Božo Kolonja and Dejan Stevanović: Maximizing the net present value by applying an optimal cut-off grade for long- term planning of the copper open pits 50 Fig. 1. Steps in planning per circular analysis [4]. When planning the mining of copper ore, the final result depends on the perception of the whole
Read MoreOtherwise, by deducting the tonnage of the ore mined from the higher-grade fine ranges, the optimum cut-off grade and the fractionation of the waste ore from the sub-optimum, the amount of tonnage of the mineral input to the processing plant is calculated. For each year, the tonnage must be recalculated for each of the brightness ranges.
Read MoreThere is a disconnect here with Cut Off Grade for generating the edge of an ore cone and the Minimum Mine (ROM) Grade for profit. The profit is assumed in generating Ore and Waste but the two are ...
Read More3 Mineral Reserves are estimated at a cut-off grade varying from $18.00 to $21.33 NSR/t of ore. Au = US$1,300/oz and Ag = US$16/oz) and an exchange rate of US$ / $ 0.75). 5 A minimum mining width of 5 m was used. 6 Bulk density of ore is variable and averages 3.07 t/m3.
Read More3.8 Copper ore mining: production and ore grade, 1971-72 to 2006-07 53 3.9 Gold ore mining: production and ore grade, 1971-72 to 2006-07 53 3.10 Silver/Lead/Zinc ore mining: smoothed production and ore grade, 1971-72 to 2006-07 54 3.11 Estimated yields in Australian mining, by industry 60 3.12 Estimated yield in Australian mining 61
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