Technology of manufacturing alloys from industrial wastes

During the last years the Physical Technological Institute of Metals and Alloys of National Academy of Sciences of Ukraine has intensively been working in the field of manufacturing metals and alloys from different industrial wastes by a method of reducing oxides of metals in iron-carbon melt.

Among numerous wastes of the economic activity a special place is occupied by high toxic wastes containing in particular such metals as Cd, V, Co, Pb, Hg, Mo and others. In this connection the problem of utilizing the referred to above wastes in particular electroplating sludge is one of the most important for industrialized countries including Ukraine.

The fulfilled analysis of the compositions of electroplating sludge and worn-out catalysts from some Ukrainian enterprises has shown that all wastes by their chemical composition are close to polymetallic ores, and therefore, for their processing metallurgical technologies can be used.

The investigation of peculiarities of the technological process of remelting different wastes and melting alloys can be conducted in a plasma furnace. As a reductant in this case carbon in the form of electrode breakage is used.

It has been revealed that during melting at the arc current of 200-600 A up to 70 % of volatile matters is withdrawn from sludge and up to 30 % of a solid concentrate consisting from metal and sludge is formed.

The yield of metallic base and its chemical composition obtained show that at remelting electroplating sludge a high yield of metallic base with a high content of Cr and Ni is achieved.

In future alloys melted of sludge have been used for melting alloy cast irons and steels. Chemical composition of manufactured melted cast irons and steels is close to the composition of alloys, regulated by acting normative documents.

More effective process is the use of electroplating sludge in charge during melting, where an intermediate metallurgical process stage is excluded. In this case the withdrawal of volatile matters and reduction of metal oxides is carried out in iron-carbon melt during melting.

It should be noted that the base metal Cr and Ni are reduced in iron-carbon melt adequately and the degree of their reduction amounts to 80-90 %.

The implemented investigations gave an opportunity to develop scientific fundamentals for elaborating a technology of manufacturing alloys with the use of industrial wastes.

Thus, metallurgical technologies of processing industrial wastes enable to accomplish the following tasks:

• to withdraw volatile matters from different organic and inorganic compounds;

• to extract metallic base from sludge, containing deficit alloying elements;

• to eliminate the influence of toxic wastes on environment in places of their formation.

4.	Translate the following word combinations into English, using the words in the box:

гальванічний шлам, промислові відходи, залізно-вуглецевий розплав, відпрацьований каталізатор, хімічний склад, електродний скрап, твердий (сухий) концентрат, леткі речовини, легуючі елементи, леговані сталі, оксид металу, неорганічна сполука, металева основа, плазмово-дугова електропіч, поліметалічні руди, струм дуги.

inorganic current steels base solid ores oxides polymetallic iron-carbon alloying compound metallic electrode metal volatile worn-out elements electroplating alloy furnace chemical industrial wastes arc sludge melt plasma matters composition breakage concentrate catalysts

5.	Check if you know what the following letters stand for. Match the following elements with their description.

Cd – Cadmium, кадмій	a heavy, silvery element, group 12, d-block, period 6, atomic number 80, the only metallic element that is liquid at standard conditions for temperature and pressure.
V – Vanadium, ванадій	a soft, malleable and heavy post-transition metal, atomic number 82, group 14 (carbon group), p-block, period 6, has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed to air, has a shiny chrome-silver luster when it is melted into a liquid, is also the heaviest non-radioactive element.
Co – Cobalt, кобальт	soft, bluish-white transition metal, alternatively considered a post-transition, atomic number 48, period 5, chemically similar to the two other stable metals in group 12, zinc and mercury, shows a low melting point compared to transition metals.
Pb – Plumbum, свинець	gray metallic transition metal, atomic number 42, group 6, d-block, period 5, solid phase, melting point 2896 K (2623 C, 4753 F), does not occur naturally as a free metal on Earth.
Hg – Hydrargyrum, ртуть	a hard, lustrous, gray transition metal, atomic number 27, is found in the Earth's crust only in chemically combined form, group 9, d-block, period 4, melting point 1768 K ​(1495 °C, 2723 °F).
Mo – Molybdanum, молібден	hard, blue-silver-grey, ductile and malleable transition metal, atomic number 23, group 5, d-block, period 4, is found in nature only in chemically combined form, melting point 2183 K (1910 °C, 3470 °F).

6.	Find in the box the endings of the collocations that start from the following verbs. Translate them into Ukrainian.

1) to manufacture ..., 2) to reduce ..., 3) to utilize ..., 4) to remelt ..., 5) to elaborate ..., 6) to withdraw ..., 7) to extract ..., 8) to contain ..., 9) to eliminate ....

a) electroplating sludge, b) wastes, c) deficit alloying elements, d) metallic base from sludge, e) oxides, f) volatile matters, g) technology, h) the influence of toxic wastes, i) metals

Task 7.

Give Ukrainian equivalents to the following words and word combinations. Make up 3-5 sentences with some of them.

intensively, field of manufacturing, industrial wastes, method of reducing, iron-carbon melt, numerous, to occupy, to contain, the problem of utilizing, to include, enterprise, chemical composition, polymetallic ores, processing, investigation, peculiarity, remelting, alloys, plasma furnace, a reductant, arc, volatile matters, sludge, yield, to obtain, cast irons and steels, charge, to exclude, reduction of metal oxides, to enable, to accomplish, to eliminate, influence, environment.

8.	Complete the following sentences with the missing words. Translate the sentences.