A method of making steel by deeply dephosphorization in a hot metal tank and decarburization using semi-steel with nearly zero phosphorus load in a converter includes the following steps: putting an efficient dephosphorization agent into the hot metal tank in advance, and conducting dephosphorization during blast furnace tapping and transportation of blast furnace hot metal by the hot metal tank to obtain semi-steel with [P] less than 0.04 wt. % and [C] greater than or equal to 3.5 wt. %; and removing dephosphorization slag, and pouring the semi-steel into the converter for decarburization to obtain molten steel. The efficient dephosphorization agent includes iron oxide scale, lime, and composite calcium ferrite. According to the method, a phosphorus content of the blast furnace hot metal is reduced to be less than or equal to 0.04 wt. % through the efficient dephosphorization agent.

A method for producing low-carbon ferromanganese capable of achieving a high Mn yield. In producing low-carbon ferromanganese by blowing an oxidizing gas from a top-blowing lance onto a bath face of high-carbon ferromanganese molten metal accommodated in a reaction vessel provided with a top-blowing lance and bottom-blowing tuyere to perform decarburization, the slag composition during the blowing is adjusted so that a value of (CaO+MgO)/(Al.sub.2O.sub.3+SiO.sub.2) on a mass basis in the slag composition is not less than 0.4 but not more than 5.0. Also, agitation is performed under a condition that an agitation power density ε of an agitation gas blown through the bottom-blowing tuyere is not less than 500 W/t.

A method for producing low-carbon ferromanganese capable of achieving a high Mn yield. In producing low-carbon ferromanganese by blowing an oxidizing gas from a top-blowing lance onto a bath face of high-carbon ferromanganese molten metal accommodated in a reaction vessel provided with a top-blowing lance and bottom-blowing tuyere to perform decarburization, the slag composition during the blowing is adjusted so that a value of (CaO+MgO)/(Al.sub.2O.sub.3+SiO.sub.2) on a mass basis in the slag composition is not less than 0.4 but not more than 5.0. Also, agitation is performed under a condition that an agitation power density ε of an agitation gas blown through the bottom-blowing tuyere is not less than 500 W/t.

Disclosed is a method for controlling a Ti concentration in a steel when manufacturing a silicon-deoxidized steel comprising 0.1 to 3% by mass of Si and 0.0001 to 0.005% by mass of Al by ladle refining of a molten steel, the method including the step of: adding an oxide including TiO.sub.2 to a slag in a ladle during the ladle refining, wherein the slag produced at end of the ladle refining satisfies formulas (1) to (7) below:

0.5≦CaO/SiO.sub.2≦1.8  (1)

4% by mass≦Al.sub.2O.sub.3≦20% by mass  (2)

MgO≦15% by mass  (3)

1.5% by mass≦TiO.sub.2≦10% by mass  (4)

CaO+SiO.sub.2+Al.sub.2O.sub.3+MgO+TiO.sub.2≧90% by mass  (5)

0.4≦TiO.sub.2/MnO≦5  (6)

1≦TiO.sub.2/T.Fe≦10  (7)

where a compound represented by a chemical formula represents the content of the compound in percent by mass; and T.Fe represents the total concentration, in mass ratio, of Fe contained in Fe oxides in the slag.

Process for manufacturing a slag conditioning agent for steel desulfurization wherein a dried slag material obtained from secondary steelmaking process is mixed with quicklime particles to produce a slag conditioning agent.

A monitoring method of a steelmaking process in a steelmaking vessel, wherein matters Mn, each having its respective properties PMn, are charged into said steelmaking vessel so as to produce a liquid steel and a slag.

A monitoring method of a steelmaking process in a steelmaking vessel, wherein matters Mn, each having its respective properties PMn, are charged into said steelmaking vessel so as to produce a liquid steel and a slag.

PGM converting process and jacketed rotary converter. The process can include low- or no-flux converting; partial pre-oxidation of PGM collector alloy; 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. The converter can include an inclined converter pot mounted for rotation; a refractory lining; an opening in a top of the pot to introduce converter feed; a lance for injecting oxygen-containing gas into the alloy pool; a heat transfer jacket 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.

PGM converting process and jacketed rotary converter. The process can include low- or no-flux converting; partial pre-oxidation of PGM collector alloy; 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. The converter can include an inclined converter pot mounted for rotation; a refractory lining; an opening in a top of the pot to introduce converter feed; a lance for injecting oxygen-containing gas into the alloy pool; a heat transfer jacket 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.

Systems and methods are described in which spent pickle liquor from metal cleaning processes is utilized to regenerate a lixiviant used to recover valuable metals from industrial waste and other sources. The spent pickle liquor is neutralized and solvated metals in the spent pickle liquor are precipitated in this process. When the industrial waste is slag from a metal refining process a partially closed metal production process can be implemented, where spent pickle liquor from cleaning of the refined metal is used to regenerate a lixiviant used to recover a different, valuable metal from a waste slag of the process, with precipitated salts from the lixiviant regeneration being returned as a raw material in the metal refining process. As a result waste streams from these processes are dramatically reduced or eliminated.