Scrap Processing Research Articles

Recycling of non-ferrous metals

The necessity to reclaim and recycle nonferrous metals is discussed. Scrap sources are analysed and the appropriate scrap processing examined. Outline procedures for the recycling and refining of aluminium, copper, zinc, lead, tin, precious metals, titanium, and refractory metals from their various waste sources are reviewed, and brief comments on the latest developments are included. Finally, there is an examination of the treatment of process effluents, domestic refuse, and scrapped cars for reclaiming the associated non-ferrous metals.

Self-cleaning non-ferrous metal separator

A separator is described which removes magnetic particles from the mixed feed material in addition to separating metals from non-metals. The application of this separator to automobile scrap processing is discussed.

Review Lecture: Metal recycling from scrap and waste materials

Out of a total U. K. consumption of 2.5 million tonnes per annum (Mt/a) of non-ferrous metals with a value of about £1300 M, as much as 33% with a value of £300-400 M, is recovered from scrap. The structure of the industry which makes this important contribution to the economy is briefly outlined and the paper describes the technology by which the various non-ferrous metals are recovered in re-usable form from waste materials. Sections dealing with the following metals provide data on tonnages treated, descriptions of scrap arisings and the processes oper­ated for metal extraction and refining - copper, aluminium, lead, zinc, tin and precious metals. Reference is made to difficulties encountered and the efficiency of reclamation, such as the small amount of zinc recycled as metal. Under future developments, the possible wider use of oxygen in copper refining and hydrometallurgical processing of high value and complex scrap are discussed. Mention is made of the potential for metal recovery for domestic refuse and the rôle of the Waste Management Advisory Council is described.

The recycling of metals—I. Ferrous metals

This paper treats the recycling of ferrous metals as an integral part of the iron and steel industry. The flows of home, prompt industrial and old scrap are analyzed. The industrial organization of ferrous scrap recycling is also described. Scrap is one of the two major raw materials of the iron and steel industry. The various steelmaking processes however, consume scrap in different ratios to other raw materials in the charge. The price sensitivity of scrap and the growing importance of automotive scrap are also considered. The advantages of using scrap in steelmaking include savings of energy, pollution abatement measures and processing which would otherwise be required in producing raw iron in the blast furnace. As a disadvantage, scrap can cause technical difficulties by introducing impurities into the steel. The paper also deals with international aspects of ferrous scrap markets. Finally, it assesses the supply-demand relation as a function of such developments as the shift in the balance of steelmaking processes, the adoption of continuous casting, the use of prereduced ores and further improvements in the processing of ferrous scrap.

Functional Components of the Ferrous Scrap Industry in a Selected Portion of the Southeastern U. S.

In recent years, new electric steel mills have been built and total electric steel mill production has increased substantially in the south- eastern United States. For several years, the Southeast has been an excess producer of ferrous scrap—the basic raw material used in electric steel mill production. (1) Ferrous scrap, particularly scrap steel, can be used in varying quantities in all types of steel-making furnaces: the open-hearth, electric, basic oxygen (BOF), and Bessemer. Only electric- arc steel-making furnaces, however, are currently used in the area con- sidered by this paper, and they are charged almost exclusively with steel scrap. Electric furnace steel producers depend almost exclusively on the scrap industry for their basic raw material. Purchased scrap con- sumption for electric mills ranges from 75 to 100 percent of the total scrap consumed, depending on whether or not mill-revert scrap is con- sidered as a separate source. Cast iron is not purchased or consumed by steel mills. For the most part, it is bought and used by large foundries located in the Birmingham-Anniston, Alabama, area. STUDY AREA. This paper focuses on the functional components of the ferrous scrap industry currently providing essential raw materials for five electric steel mills located in three Southeastern states. These five steel producers are located in a relatively compact geographical area within Georgia, South Carolina, and North Carolina. Since all five mills are electric, they are dependent on ferrous scrap as a raw material. The outer boundary of their collective raw materials supply area thus serves

Fluxes in the scrap process

Fluxes in the scrap process

Oh! Where Have the Mountains of Titanium Scrap Gone?

Results of a secondary titanium market survey indicated that an oversupply of titanium scrap does not exist. The mountains of scrap that existed during the late 1950’s and early 1960’s were consumed down to mole hills by the mid to late 1960’s. During the past two and one-half years, even the mole hills’ roots were consumed. The titanium scrap situation is illustrated by a 10-year statistical model (see Table I). The model in the form of a table contains sponge, ingot, and scrap production and consumption statistics. Three assumptions were used, two concerned with fabrication productivity and the third with nonrecoverable scrap losses. Over the total 10-year period, scrap consumption was larger than scrap supply by 7.6%. For the first six years, 18% more scrap was consumed than was generated. For the last four years, scrap supply and demand were in balance, almost within 100 tons. Currently (1969–1970), scrap is in short supply. For the future, table data trends indicate that the short supply will continue. A major effect of the tight supply will be upward pressure on the price of ingot. Scrap is migrating to the steel (including direct alloying and deoxidizing, ferrotitanium production, and exports) and aluminum industries, instead of returning for recycling, because of lower scrap processing costs and technological needs for titanium metal which cannot be met with sponge.

Progress in scrap processing

Progress in scrap processing

Multi-chamber furnaces heated by an electron beam: K Schmidt,Proc First Nat Conf Electro-Heat, Prague, Nov 1966, ( in German)

In investment casting processes for TiAl alloys, a substantial amount of the original raw material does not end-up as a final product but is instead solidified in runners and feeders of the casting system or as a skull in the crucible. Because of the high prices for the virgin alloys, there is a strong interest in remelting this scrap. This is a challenging task due to the tremendous oxygen affinity of titanium alloys. The contact of the melt with shell mould and crucible material leads to oxygen pickup during casting. Up to now no technique exists to avoid this effect, thus any recycling process for TiAl casting scrap potentially needs a deoxidation technique. Within the IMPRESS project, experimental proof for the feasibility of a novel treatment has been obtained in a series of tests and results are presented in this paper. Casting scrap from pilot-trials has been consolidated via classic vacuum induction melting (VIM) in special ceramic crucibles and then successfully deoxidized by pressure electroslag remelting (PESR) under reactive slags. Further refining by vacuum arc remelting (VAR) finally leads to removal of dissolved reducing agent and impurities like non-metallic-inclusions.

Rapid determination of nitrogen in steels by vacuum metlting extraction: H Severus-Laubenfrid et al, Z Anal Chem, 218, 1966, 241–249 ( in German)

In investment casting processes for TiAl alloys, a substantial amount of the original raw material does not end-up as a final product but is instead solidified in runners and feeders of the casting system or as a skull in the crucible. Because of the high prices for the virgin alloys, there is a strong interest in remelting this scrap. This is a challenging task due to the tremendous oxygen affinity of titanium alloys. The contact of the melt with shell mould and crucible material leads to oxygen pickup during casting. Up to now no technique exists to avoid this effect, thus any recycling process for TiAl casting scrap potentially needs a deoxidation technique. Within the IMPRESS project, experimental proof for the feasibility of a novel treatment has been obtained in a series of tests and results are presented in this paper. Casting scrap from pilot-trials has been consolidated via classic vacuum induction melting (VIM) in special ceramic crucibles and then successfully deoxidized by pressure electroslag remelting (PESR) under reactive slags. Further refining by vacuum arc remelting (VAR) finally leads to removal of dissolved reducing agent and impurities like non-metallic-inclusions.

Container for the degasification of steel and other metals: A Sickbert, ( Bochumer Verein fuer Luststahlfabrikation) German Patent 1,217,987 June 1966, Appl Nov 2 1961 3 pages

In investment casting processes for TiAl alloys, a substantial amount of the original raw material does not end-up as a final product but is instead solidified in runners and feeders of the casting system or as a skull in the crucible. Because of the high prices for the virgin alloys, there is a strong interest in remelting this scrap. This is a challenging task due to the tremendous oxygen affinity of titanium alloys. The contact of the melt with shell mould and crucible material leads to oxygen pickup during casting. Up to now no technique exists to avoid this effect, thus any recycling process for TiAl casting scrap potentially needs a deoxidation technique. Within the IMPRESS project, experimental proof for the feasibility of a novel treatment has been obtained in a series of tests and results are presented in this paper. Casting scrap from pilot-trials has been consolidated via classic vacuum induction melting (VIM) in special ceramic crucibles and then successfully deoxidized by pressure electroslag remelting (PESR) under reactive slags. Further refining by vacuum arc remelting (VAR) finally leads to removal of dissolved reducing agent and impurities like non-metallic-inclusions.

Scrap Melting by the Fuel-Oxygen-Scrap Process

A brief description of BISRA’s recently announced FOS (Fuel-Oxygen-Scrap) process for melting scrap and making steel from a cold charge.

LD and LDAC Operating Experience in Britain

Operating experience of both LD and LDAC steelmaking at the Ebbw Vale works of Richard Thomas and Baldwins Ltd. is presented. The two processes are compared as to (1) hot-metal and finished steel analysis, (2) lining consumption, (3) overall process yield, (4) Urne, oxygen, and scrap consumption, (5) iron losses to the slags, and (6) production rates. Present knowledge of both the LD and LDAC processes indicates that a powdered-lime injection, foaming-slag practice would be the preferred method of controlled operation with respect to input materials, steel analysis, and ease of operation. This single-phase LDAC process is applicable to hot metals containing up to 0.60% P.

The use of manganese ore in the scrap process with low-manganese irons

The use of manganese ore in the scrap process with low-manganese irons

The efficiency of blowing compressed air into the open-hearth furnace bath in the scrap process

The efficiency of blowing compressed air into the open-hearth furnace bath in the scrap process