FACULTY OF PRACTICAL SCIENCE.

ORE DRESSING.

1. (a) Write notes upon the action of these rock breakers: The Blake, The Dodge, and gyratory crushers.

(b) What position have they in the flow sheet of a mill?

2. Answer the following questions concerning rolls: (a) What governs the size of their feed and their product?

(b) What governs their capacity?

(c) What is the nature of their crushing?

(d) What are causes of variation in the angle of nip?

3. (a) What machines or combination of machines have been proposed to replace the ordinary five-stamp gravitystamp battery to crush gold ores?

(b) Give the advantages of the gravity stamp battery over the different machines mentioned in 3 (a).

(c) Write briefly on the following parts of a stamp battery; cam, shoe, mortar, and foundation.

4. An ore, 3" diameter, consists of 10% galena and calcite gangue; jigging may be commenced at 1⁄2 inch, and grinding to 60 mesh is necessary to liberate all the galena.

(a) Outline the mill process you would propose to recover the galena in the ore.

(b) Describe the machine you would use to grind the material to 60 mesh.

5. Explain briefly to distinguish between, sizing, classification, and hindered settling, and at what point in a mill process is each operation or condition found?

6. (a) Name different properties possessed by various minerals which are made use of to effect their separation from different minerals and gangue.

(b) Mention, without describing, a machine that is constructed to separate minerals according to each of the different properties mentioned in 6 (a).

(c) Explain the principle of operation of one of the machines mentioned in 6 (b).

7. How are coals classified? Give a classification.

MINING II.

1. (a) Where might one expect to find placer gold, and what are its closest associations?

(b) Summarize the chief features of individual Placer Mining; of Hydraulic Mining; and of Gold Dredging.

(c) Define: Bedrock; Penstock; Miner's inch; Wing dam.

2. Sketch (with a few side notes) a tunnel set of timbers in place; also a shaft set; a stull, and a square set in place.

or,

Describe carefully the support of stope walls, by stulls; square sets; and filling with waste or sands.

3. Explain how you would compute the flow in a drainage tunnel; and also the capacity in gallons per minute, and lift of a mine pump.

4. In the matter of mining transportation, describe briefly but closely the conditions of the route, and means of carrying ore from its place in a stope, between levels, to the ore bins at the surface.

5. What are the chief reasons for using these following means of transportation:

Conical drums; Whiting sheave hoists; aerial tramways; McGinty's or gravity railroads in a coal mine; compressed air locomotives; main and tail haulage?

6. Explain clearly the physical conditions which cause. natural ventilation in mines; also explain the use of the water gauge in coal mines, and show how the quantity of air passing into the mine is arrived at through its use.

7. It is quite common for people to figure out the average grade of an ore by dividing the aggregate amount of the assays by the number of them. Explain the error of this; also explain the errors often made by using the New York price of metals on an assay certificate as the value of the

ore.

8. Define: Option; bond; positive ore; probable ore; possible ore; amortization; preferred shares; common shares.

METALLURGY I.

FACULTY OF PRACTICAL SCIENCE.

1. Define calorific power, calorific intensity, heat of formation of a chemical compound, thermal equation, endothermic reaction.

2. Determine the heating value per cubic meter of a gas containing 90% by volume of CH, and 10% by volume of H2. When you know a molecular weight in kilograms of any gas occupies 22.22 cubic meters, and that the heat of formation of CH, 22250, CO, 97000, H2O (gaseous) =58000.

3. What is pyrometry? Discuss two methods of reading temperatures between 1000 and 1500°C, and one for reading temperatures from 1700 to 2500°C.

4. Compare the relative advantages of manufacturing coke in the beehive and in a modern by-product coke oven. Discuss the method of manufacturing it in the latter. Why is coke made?

5. Discuss the operation of an ordinary water-bottom gas producer of the Dawson type. Mention the chemical reactions that take place in the various zones of this producer.

6. Discuss the manufacture of pig iron in the modern blast furnace. What are the rincipal grades of pig iron sold on the market?

7. What are the effects of the following elements on the properties of cast iron, combined carbon, graphite carbon, silicon, sulphur, manganese, and phosphorus?