Tons of melt

A homogeneous glass mass containing 25 - 60% by volume of gas inclusions is produced in the SCM. The melting temperature reaches about 1600°C. The specific productivity of about 15 tons of melt per 1 m of melt flee surface was reached for SCMs with a working volume of 4 - 8 m and a melt free surface area of 2 - 4 m. ... 

Uses. The sinter oxide form is used as charge nickel in the manufacture of alloy steels and stainless steels (see Steel). The oxide furnishes oxygen to the melt for decarburization and slagging. In 1993, >100, 000 metric tons of nickel contained in sinter oxide was shipped to the world s steel industry. Nickel oxide sinter is charged as a granular material to an electric furnace with steel scrap and ferrochrome the mixture is melted and blown with air to remove carbon as CO2. The melt is slagged, pouted into a ladle, the composition is adjusted, and the melt is cast into appropriate shapes. A modification of the use of sinter oxide is its injection directiy into the molten metal (33). 

With the introduction of mechanical refrigeration, the term ton was retained. The owner could now buy a system capable of providing the equivalent capacity of hov/ever many tons was needed. Since one pound of ice absorbs 144 Btu when melting, one ton of ice melting over a period of 24 hours has a heat transfer rate equivalent to the following ... 

Ton of refrigeration The heat equivalent to melting 2,000 lb (one ton) of ice in 24 hours. One ton equals 12,000 Btu/hr or 200 Btu/min. To be comparative, refrigeration equipment must have the refrigerant level (or evaporation temperature) specified. 

In 2002, the world production of polymers (not including synthetic libers and rubbers) was ca. 190 million metric tons. Of these, the combined production of poly(ethylene terephthalate), low- and high-density polyethyelene, polypropylene, poly(vinyl chloride), polystyrene, and polyurethane was 152.3 milhon metric tons [1]. These synthetic, petroleum-based polymers are used, inter alia, as engineering plastics, for packing, in the construction-, car-, truck- and food-industry. They are chemically very stable, and can be processed by injection molding, and by extrusion from the melt in a variety of forms. These attractive features, however, are associated with two main problems ... 

Secondary raw materials recovered from scrap are more concentrated and more pure than primary raw materials. Scrap is already in the metallic form, and requires only purification which, in the most favorable or desirable cases, involves only melting. The recovery of secondary metals can, therefore, be carried out with fewer and simpler operations, consuming a smaller amount of energy and causing less pollution, than primary metals production. For example, the production of 1 ton of copper from ore consumes about 116 GJ of energy, while the consumption is only about 19 G J when the production is from scrap. 

The primary leachable hazardous constituents of EAF emission control dust/sludge are lead, cadmium, and hexavalent chromium. Generally, 20 to 40 lb of EAF dust per ton of steel are generated, depending on the mill s specific operating practices, with an average of about 35 lb/t of steel melted.1 Table 2.11 shows the typical ranges of concentration of each of these elements in EAF dust. 

The 6180 in Byrd core melted ice as a function of depth has been measured by mass spectrometry [4,5]. Since the 6180 scale depends on the temperature of the ocean water that developed into snow flakes [6], accurate dating of the core itself is necessary to reveal the temperature history of the ocean surface water. Oeschger et al., [7] measured the 14C contents of C02 extracted from 3 tons of ice melted i n situ, at depths of 100, 175, 270, and 380 m near the Byrd site, their 14C ages for 270- and 380-m depths are 1300 700 and 3000 500 years, respectively. 

Scientists now project that within the next few decades, the capacity of the earth and the oceans to absorb carbon emissions will decline, while vast changes in the Arctic may further accelerate warming. Melting tundra will release millions of tons of methane, a greenhouse gas more powerful than C02. 

Table 5.1 summarizes the uses of lime. Lime is used as a basic flux in the manufacture of steel. Silicon dioxide is a common impurity in iron ore that cannot be melted unless it combines with another substance first to convert it to a more fluid lava called slag. Silicon dioxide is a Lewis acid and therefore it reacts with the Lewis base lime. The molten silicate slag is less dense than the molten iron and collects at the top of the reactor, where it can be drawn off. Over 100 lb of lime must be used to manufacture a ton of steel. 

Similarly, a turn-over frequency (TON) of 227 of the polymerization process was distinctly low for 77d with [M]/[I] = 350, at 110 °C for 6 h, using in the melt polymerization conditions. Biocompatible calcium complex 77a used as catalyst at 110 °C produced in 30 min PLAs with high molecular weight (65,000-110,600) and narrow polydispersities (1.02-1.05) using [M]/[I] = 350-700. It is worthy of note that complex 77a displayed a notable heteroselectivity (probability of racemic linkages between monomers, = 0.73, see Sect. 4.2) in polymerization of rac-lactide in THF at 33 °C. Data on the aforementioned calcium initiators and their lactide polymerization are listed in Table 4. 

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