C21C5/36

Process and system for eliminating the potential for LD and EAF steel slag expansion

A process and system having a primary crusher to reduce the fragments according to their granulometry; a magnetic separator to remove metallic fragments bigger than a determined granulometry; a rotary dryer to dry slag; an impact mill to disaggregate and fragment slag particles; a classifier for aero-classification and drag of fine and superfine particles; a cooler for cooling slag by means of heat exchange and removal of the fine and superfine particles that were not collected by the impact mill a vibrating sieve provided with two or more decks with screens of predetermined sizes; low-intensity magnetic separators, with generation of non-magnetic slag fractions free from metallic iron and from iron monoxide, and of magnetic fractions composed by metallic iron and iron monoxide; and low-intensity magnetic separators to reprocess the magnetic fractions with generation of concentrate with high metallic iron contents and a product with high concentration of iron monoxide.

Integrated PGM converting process
10513751 · 2019-12-24 · ·

Integrated PGM converting process. The process includes smelting a catalyst material in a primary furnace, smelting the primary furnace slag in a secondary furnace, converting the collector alloys from the primary and secondary furnaces in a converter to recover PGM enriched alloy and converter slag, separating the recovered converter slag into first and second converter slag portions, and supplying the first converter slag portion to the secondary furnace for smelting with the primary furnace slag. The process can also include low- or no-flux converting; refractory protectant addition; magnetic slag separation; partial feed pre-oxidation; staged slagging; and/or jacketing the converter.

PGM converting process with staged slagging
10513750 · 2019-12-24 · ·

The process includes melting an initial collector alloy charge to start a converter cycle, introducing feed and injecting oxygen into the alloy pool, allowing ferrous slag to collect, terminating feed introduction and oxygen injection to tap the slag, repeating the feed introduction/oxygen injection/slag tapping sequence a plurality of times, and then tapping the alloy to end the cycle. A delay before non-final slag tappings allows any entrained alloy to settle back into the alloy pool, but the final slag tapping is commenced promptly and alloy is optionally entrained. Slag from the final tapping that may contain entrained alloy can be recycled to the converter, e.g., in a subsequent cycle. The process can also include low- or no-flux converting; refractory protectant addition; slag separation; partial feed pre-oxidation; smelting the slag in a secondary furnace with primary furnace slag; and/or jacketing the converter.

Process for manufacturing a slag conditioning agent for steel desulfurization

A process for manufacturing a slag conditioning agent for steel desulfurization is shown in which a dried slag material Obtained from a secondary steelmaking process is mixed with quicklime particles. The quicklime particles react with moisture in the slag material to dry the slag material and produce a blend of slag material, hydrated lime and any unreacted quicklime. The blend is then sieved to separate out the hydrated lime. The retained dried fraction after sieving is then mixed with an Al.sub.2O.sub.3 mass fraction from which the slag conditioning agent can be collected. The slag conditioning agent has an equivalent mass ratio which is between 0.55 and 1.5.

MOLTEN IRON REFINING METHOD

A molten iron refining method having, an auxiliary material, and an oxidizing gas supplied through a top-blowing lance, to a cold iron source and molten pig iron that are contained/fed in a converter-type vessel, and molten iron is subjected to a refining process. A pre-charged cold iron source is charged into the converter-type vessel at an amount not larger than 0.15 times. A furnace-top-added cold iron source that's part or all of the cold iron source and added from a furnace top is fed during the refining process. A burner at a leading end of the top-blowing lance that spray holes through which a fuel and a combustion-supporting gas are ejected. During the refining process, a powdery auxiliary material processed into powder that's part of the auxiliary material is blown in, to pass through a flame formed by the burner.

MOLTEN IRON REFINING METHOD

A molten iron refining method that prevents a cold iron source from remaining unmelted even under the condition of a high ratio of the cold iron source. An auxiliary material is added, and an oxidizing gas is supplied, to cold iron source and molten pig iron that are contained or fed in converter-type vessel, and molten iron is subjected to refining process. Prior to refining process, a pre-charged cold iron source that is charged all at once into the converter-type vessel before the molten pig iron is charged into the converter-type vessel is charged in an amount not larger than 0.15 times the sum of an amount of the pre-charged cold iron source and a charge amount of the molten pig iron, or is not charged. A furnace-top-added cold iron source that is added from a furnace top of the converter-type vessel is fed into converter-type vessel during refining process.

Converting process with slag separation and recycle
10501823 · 2019-12-10 · ·

Converting process with slag separation and recycle to the converter. The process includes introducing converter feed into the pot holding a molten alloy pool, oxygen injection into the pool, tapping the slag, and tapping the PGM-enriched alloy. The collector alloy contains no less than 0.5 wt % PGM, 40 wt % iron, and 0.5 wt % nickel, and no more than 3 wt % sulfur and 3 wt % copper, and the recovered slag is separated into recycle and non-recycle portions. The recycle slag portion preferably contains more PGM than the non-recycle portion. The process can also include low- or no-flux converting; using a refractory protectant in the converter; magnetic separation of slag; partial pre-oxidation of the converter feed; smelting catalyst material in a primary furnace to produce the collector alloy; and/or smelting the converter slag in a secondary furnace with slag from the primary furnace.

Converting process with partial pre-oxidation of PGM collector alloy
10472700 · 2019-11-12 · ·

Converting process with partial pre-oxidation of PGM collector alloy. The process includes partially pre-oxidizing a raw alloy, introducing an initial charge of the partially pre-oxidized alloy into a converter pot, melting the initial charge, introducing converter feed to the pool, oxygen injection into the pool, tapping the slag, and tapping the PGM-enriched alloy. The collector alloy contains no less than 0.5 wt % PGM, 40 wt % iron, and 0.5 wt % nickel, and no more than 3 wt % sulfur and 3 wt % copper. The process can also include low- or no-flux converting; using a refractory protectant in the converter; magnetic separation of slag; recycling part of the slag to the converter; smelting catalyst material in a primary furnace to produce the collector alloy; and/or smelting the converter slag in a secondary furnace with slag from the primary furnace.

Jacketed Rotary Converter and PGM Converting Process
20190338380 · 2019-11-07 ·

Jacketed rotary converter. The converter includes an inclined pot mounted for rotation about a longitudinal axis, a refractory lining for holding a molten alloy pool, an opening in a top of the pot for introducing feed, a lance for injecting oxygen-containing gas, a heat transfer jacket for the pot adjacent the refractory lining, and a coolant system to circulate a heat transfer medium through the jacket to remove heat from the alloy pool in thermal communication with the refractory lining. Also disclosed is a PGM converting process using the jacketed rotary converter. The process can also include low- or no-flux converting; refractory protectant addition; slag separation; partial feed pre-oxidation; staged slagging; and/or smelting the slag in a secondary furnace with primary furnace slag.

Jacketed Rotary Converter and PGM Converting Process
20190338380 · 2019-11-07 ·

Jacketed rotary converter. The converter includes an inclined pot mounted for rotation about a longitudinal axis, a refractory lining for holding a molten alloy pool, an opening in a top of the pot for introducing feed, a lance for injecting oxygen-containing gas, a heat transfer jacket for the pot adjacent the refractory lining, and a coolant system to circulate a heat transfer medium through the jacket to remove heat from the alloy pool in thermal communication with the refractory lining. Also disclosed is a PGM converting process using the jacketed rotary converter. The process can also include low- or no-flux converting; refractory protectant addition; slag separation; partial feed pre-oxidation; staged slagging; and/or smelting the slag in a secondary furnace with primary furnace slag.