Sorbent components containing halogen, calcium, alumina, and silica are used in combination during coal combustion to produce environmental benefits. Sorbents such as calcium bromide are added to the coal ahead of combustion and other components are added into the flame or downstream of the flame, preferably at minimum temperatures to assure complete formation of the refractory structures that result in various advantages of the methods. When used together, the components reduce emissions of elemental and oxidized mercury; increase the level of Hg, As, Pb, and/or Cl in the coal ash; decrease the levels of leachable heavy metals (such as Hg) in the ash, preferably to levels below the detectable limits; and make a highly cementitious ash product.

A system and method for recovering sulfur in a copper smelting process, in which fine dust is removed from high-concentration SO.sub.2 flue gas from a matte smelting furnace, the flue gas is introduced into a fluidized bed carbothermic reduction tower and reduced by a carbon-based reducing agent to obtain reducing gas, which is introduced into a high temperature separator. The separated reducing gas contains unsaturated powder coke, and the reducing gas is condensed to obtain sulfur. The saturated powder coke entrained enters a desorption tower to desorb SO.sub.2 gas, and the desorbed powder coke enters a fluidized bed sulfur reduction tower. Part of the SO.sub.2 gas discharged from the desorption tower is discharged to the fluidized bed carbothermic reduction tower to produce sulfur, and the other part is introduced into a desulfurization tower.

The present invention relates to calcium hydroxide particles having a total pore volume greater than 0.18 cm.sup.3/g, said total pore volume being calculated with the BJH method for a range of pores having a diameter of between 20 and 1000 Å, said particles being characterized in that the BJH partial pore volume for the range of pores having a diameter of between 20 and 100 Å corresponds to more than 20% of said BJH total pore volume.

Systems and methods for generation of lime hydrate compounds and particularly highly reactive hydrated lime (HRH) with a reduced resistivity through the inclusion of a sodium compound generally in the slaking water used in generating the lime hydrate or HRH. The compound may then be used in systems which include a Electrostatic Precipitator (ESP) for SO.sub.2 mitigation without many of the associated problems in ESP performance.

Sorbent components containing halogen, calcium, alumina, and silica are used in combination during coal combustion to produce environmental benefits. Sorbents such as calcium bromide are added to the coal ahead of combustion and other components are added into the flame or downstream of the flame, preferably at minimum temperatures to assure complete formation of the refractory structures that result in various advantages of the methods. When used together, the components reduce emissions of elemental and oxidized mercury; increase the level of Hg, As, Pb, and/or Cl in the coal ash; decrease the levels of leachable heavy metals (such as Hg) in the ash, preferably to levels below the detectable limits; and make a highly cementitious ash product.

The invention relates to a reactor for cleaning flue gases by a dry or quasi-dry sorption process, comprising a flue gas inlet (1) at the bottom of the reactor, an outlet (2) at the top of the reactor, a dry sorbent injection system (3) with at least one dry sorbent outlet (4) for injecting dry sorbent into the reactor, the at least one dry sorbent outlet (4) being arranged between the flue gas inlet (1) and the outlet (2).

A process to treat/clean a gas, containing SO.sub.2, CO.sub.2 and O.sub.2 comprising the steps of: bringing the gas in contact with an activated carbon catalyst, converting SO.sub.2 to SO.sub.3/H.sub.2SO.sub.4 on the activated carbon catalyst, washing the SO.sub.3/H.sub.2SO.sub.4 from the activated carbon catalyst to obtain a sulfuric acid solution and a SO.sub.2 depleted gas; bringing the SO.sub.2 depleted gas in contact with an aqueous ammonia solution wherein CO.sub.2 is converted to obtain a SO.sub.2 and CO.sub.2 depleted gas containing ammonia; and bringing the SO.sub.2 and CO.sub.2 depleted gas containing ammonia in contact with the sulfuric acid solution obtained in step a. to form a solution containing ammonium sulfate and a treated, clean gas.

This disclosure provides an apparatus to manipulate the crystal morphology of a powder to improve the flow of a powder from a vessel and/or flowability of a powder in order to achieve stable fluidization of the powder within a vessel.

A gas purification apparatus includes: a housing to which a gas is introduced; a filter portion for removing an impure substance in the gas from the gas, the filter portion being disposed inside the housing; and a gas purification agent for removing a removal target substance in the gas from the gas, the gas purification agent being disposed, inside the housing, on the filter potion or in a space at a downstream side of the filter portion with respect to a flow of the gas.

To adsorb a substance to be treated in a fluid (7) with a higher adsorption capacity and lower pressure loss, an adsorptive sintered compact (20) includes powder adsorbent materials (1a, 1b), and resin structures (2) in which voids (3) are formed in a three-dimensional network. The powder adsorbent materials (1a, 1b) include free adsorbent materials (1a) free-movably contained in the voids (3) between the resin structures (2), and fixed adsorbent materials (1b) fixed to a surface (2a) of the resin structure (2) and/or at least partly embedded inside the resin structure (2), and the powder adsorbent materials (1a, 1b) are at least one of powdered activated carbon, powdered activated clay, and zeolite.