How is gold grade calculated?
Table of Contents
How is gold grade calculated?
Understanding Gold Grading
- All precious metals are graded by the amount of metal within the ore.
- A higher grade means that it takes less effort to remove the metal from the ground.
- The World Gold Council rates gold based on ore density measured by grams per tonne, or g/t.
How is gold ore measured?
As gold usually appears in very low concentrations in mineral deposits, it is usually measured in grams per tonne, and the average ore grade can vary significantly from one mine to another. Usually open cut mines have lower grades, around 1 to 4 g/t, while underground mines can reach up to 8 to 10 g/t [36].
How do you calculate your grade ore?
The average grade of each hole is the sum of the products of each sample length by its assay value divided by the sum of the lengths. This grade, multiplied by the volume of the prism and divided by the volume-per-ton factor, gives the tons- percent or ton-dollars in the prism, as the case may be.
What is the difference between a high grade ore and a low grade ore?
What is the difference between a high grade and a low grade ore? High-grade ore contains a large concentration of the desired mineral. Low-grade ore has a smaller concentration.
How much gold is there in gold ore?
Most gold ore now comes from either open pit or underground mines. The ores sometimes contain as little as 5/100 of an ounce of gold per ton of rock.
What is grade of an ore?
The grade of ore refers to the concentration of the desired material it contains. The value of the metals or minerals a rock contains must be weighed against the cost of extraction to determine whether it is of sufficiently high grade to be worth mining, and is therefore considered an ore.
How are grades calculated?
To calculate your current letter grade, divide the points earned by the points possible. Using the example, 380 divided by 536 equals 0.71. To turn this into a percentage multiply the answer by 100 or move the decimal point over two places. This equals 71 or 71\%.
What is grade in ore deposit?
What is good grams per ton for gold?
The gold exploration industry defines a “Bonanza result” as any result above 34g of gold per tonne of rock/ore (g/t) – which is extremely high grade. Anything above 5 g/t is considered high grade, but 34 g/t Bonanza grades are a whole other level.
What is a good ppm for gold mining?
20.1 Metal Deposits
| Metal | Typical Background Level | Typical Economic Grade* |
|---|---|---|
| Gold | 0.003 ppm | 6 ppm (0.006\%) |
| Lead | 10 ppm | 50,000 ppm (5\% |
| Molybdenum | 1 ppm | 1,000 ppm (0.1\%) |
| Nickel | 25 ppm | 20,000 ppm (2\%) |