Secondary aluminium refining

In the secondary aluminum production industry, scrap aluminum is melted in gas- or oil-fired reverberatory or hearth furnaces. Impurities are removed using chlorine or other fluxes until the aluminum reaches the desired purity. Other aluminum production plants use dross in addition to scrap. Dross is a by-product of primary aluminum melting. This process further reduces the pollution resulting from primary aluminum production. It contains fluxes and varying concentrations of aluminum. "Skim," "rich," or "white dross" refer to aluminum dross with high aluminum content. "Black dross" or "salt cakes" refer to aluminum dross from practices that use salt fluxes.

The dross is crushed, screened and melted in a rotary furnace where the molten aluminum is collected in the bottom. The resulting salt slag is a waste product. To reduce this waste more of the remaining metafiles may be leached into water and collected.

To eliminate the need for salt fluxes, a new plasma torch treatment has been developed to heat the rotary furnace. High concentrations of aluminum are recovered from this procedure.

Task 1

Find in the text English equivalents to the following words:

банки для напоїв, обшивка, алюмінієва фольга, дріт, рами, очищувати, розливати, видобувати, суміш, мілко подрібнений, резервуар, осушувати, виробничі цехи, видаляти домішки, піч для вирівнювання температур, барботувати, піч для відпалу (декарбонізатор), бажана чистота, подова піч, відходи, окалина, карусельна піч.

Task 2

Match the words in column A with their translation from column B.

A	B
1. sludge	a) домішка
2. dross	b) класифікатор
3. digester	c) шлам
4. calcinator	d) розчин
5. piston	e) окалина
6. purity	f) поршень
7. impurity	g) обпалювальна піч
8. solution	h) чистота

Task 3

Give Ukrainian equivalents to the following words and word combinations.

engine, aluminum plate, packaging industry, aluminum scrap, ore, to locate, low energy costs, rolling, three step process, extract, be mixed with, to dissolve, residue, to evaporate, to condense, starch remaining impurities, precipitation tank, dewatering, electrolytic cell, to sink, holding furnace, to obtain specific characteristics, fabrication shops, to remove oxides, bubble, to reach the desired purity, by-product, reduce the pollution, fluxes, to crush, to screen, rotary furnace, waste product, to leach.

Task 4

Fill in the correct words from the list below. Use each word only once.

desired, concentrations, aluminum, melt, reverberatory, ingots,

collected, production, plasma torch, resulting, heat, by-product

1. … treatment	7. dross with high … content
2. aluminum reaches the … purity	8. cast into …
3. to … the rotary furnace	9. … salt slag
4. to refine and … the aluminum	10. aluminum … plants
5. molten aluminum is …	11. varying … of aluminum
6. … of primary aluminum melting	12. oil-fired … furnaces

Task 5

Choose in column B the proper ending to the word combinations in column A.

1. To extract from (what?) 2. To place crushed bauxite in (where?) 3. Starches are added to (for what purpose?) 4. To remove (what?) 5. To mix molten aluminum with (with what?) 6. To place aluminum oxide in (where?) 7. Aluminum oxide is crystallized in (where?) 8. The residues form (what?) 9. Scrap aluminum is melted in (where?)

a) an electrolytic cell b) a precipitation tank c) impurities d) reverberatory or hearth furnace e) desired alloys f) bauxite ore g) remove any impurities h) a sludge i) digester

Task 6

Make up the sentences from the given words. Start with the underlined word.

1. ship, Aluminum, casting, rolling, metal, producers, the, plants, ingots, for, to.

2. impurities, Oxides, removed, and, sodium, heating, aluminum, magnesium, be, from, by, molten, can.

Дата добавления: 2015-07-20