DD294009A5 - METHOD FOR THE PRODUCTION OF CEMENT LINKERS AND RECOVERY OF SULFUR DIOXIDE - Google Patents

Abstract

The invention relates to a process for the preparation of cement clinker and recovery of sulfuric acid from waste products in gypsum-sulfuric acid Prozesz. According to the invention, a clinker raw meal is used which contains CaSO 3 -containing waste products from flue gas desulphurisation plants as anhydrite substitute in proportions of 5 to 80%, and this raw meal in the rotary kiln inlet region with waste sulfuric acid in the molar ratio of H 2 SO 4: CaSO 3 of 0.2 to 1.0 . sprayed {gypsum-sulfuric acid Prozesz; raw meal; Anhydrite substitute; flue gas desulfurization; waste product; CaSO3-sustainably; Abfallschwefelsaeure}

Description

1. Conventional raw mixture of anhydrite, brown coal filter ash (OFA), sand and coke dom hour according to the technique accordingly.

2. Raw mixture according to the invention, bet% of the anhydrite 50% after mixture 1 by a üborwiogond CaSO ₃ onthnltondos Abprodukt 1 was replaced.

3. Raw mixture according to the invention, in which the anhydrite dor mixture 1 was completely replaced by oil CaSO ₍ -haltigos waste product.

4. Inventive crude mixture, boi 40% of the anhydrite after mixture 1 by a predominantly CnSOj cnthnltondos waste product 2 was replaced.

The raw mixtures are admixed with dom sulphate content of coking coal. The chemical analysis raw material and CaSOj-containing waste products is shown in Table 1.

Table 1 Raw Material Analysis

component SiO, Al ₂ O ₃ Fe ₂ O ₃ CaO sulfate sulfite SO ₃ SO ₁ anhydrite - - .. 40.4 58.8 sand 95.0 1.9 0.9 0.8 - - BFA 41.4 14.8 9.7 16.9 _ - Abprodukt 1 1.0 - - 50.0   1.0 27.0 Waste product 2 10.4 5.7 8.2 36.4 2.3 21.4

The raw mixes for the clinker brandy were listed in Table 2 as follows: Table 2: Composition of the raw mix clay

raw mix Shares in de · ¹ Raw mix /% / BFA Abprodukt 1 Waste product 2 anhydrite sand 16.1 - - 1 80.0 3.6 18.0 39.3 - 2 39.3 3.5 19.7 76.9 - 3 - 3.4 _ _ 45.5 4 48.5 6.0

The raw mixture 3 can be prepared without dry and grinding process by simple mixing. In the raw coal intake area of the rotary kiln, waste sulfuric acid is metered onto the raw mixture, resulting in the

in Table 3 SOj-Komentrationen reproduced in the furnace gas. The raw material throughput is set at 13t / h.

Table 3 Dosing of waste sulfuric acid (AS) to the raw mixtures and SOj concentration in the furnace gas

experiment Raw DosierungAS % HjSO ₄ Compressive strength / MPa / 3 days / kJ / kg clinker / 28 days furnace gas charge mixture H, SO ₄ : CaSO ₄ , 1 day 30.8 8800 50.4 Mol ratio in AS 14.8 29.5 8000 50.6 Vol .-% SO ₂ 1 1 - - 15.2 30.1 85G0 49.9 9.0 2 2 - - 14.7 30.4 7200 49.8 7.8 3 2 1.0 98 15.0 29.7 7800 49.9 10.3 4 3 - - 14.8 32.0 7650 52.9 6.5 5 3 0.5 8.4 15.3 31.5 8000 52.8 9.0 6 4 _ - 15.0 Table 5 Primary energy expenditure for the clinker fire 8.2 7 4 0.4 78 trial batch 10.8 Table 4 Strength development of cements made from the clinker 1 trial batch 2 3 1 4 2 CJL 3 6 4 7 5 6 7

Claims (3)

1. Ancestry for the production of Zomontklinker and recovery of sulfur dioxide for dio production of Portland cement and Schwofolsäuro in gypsum Schwofolsäuro prozess from raw milk and Abfallschwefolsäure, characterized in that in the raw meal CaSO ₃ -Halligo Abprodukto from Rauchgasentschwofoliingsanlagon as a substitute for anhydrite with 5 to 80 % are used and this Rohrnehl is sprayed in the Einldufbereich dos Drehrohrofons with Abfallschwofolsäuro in the molar ratio H ₂ SO ₄ ICaSOa from 0.2 to 1.0. 2. The method according to claim 1, characterized in that a CaSO ₃ -haltigos Abprodukt init 21 to 80% CaSO ₃ and 5 to 20% CaSO _{4 is} used. 3. Method n-.ch claims 1 and 2, characterized in that Abfallschwofolsäuro comes with 78 to 100% H ₂ SO ₄ ium use. Field of application of the invention The invention relates to a method for Horstollung of cement clinker and for the recovery of Schwofoldioxid in the gypsum sulfuric acid process. Characteristic of the known state of the art The production of sulfuric acid and cement clinker from anhydrite, natural gypsum, coke and aggregates such as clay, sand and iron oxide is known (Z. Angewandte Chemie 38. 794-795 (1925); 39.169-17411926); Chem. Ing. Techn. 21 227-229 (1949). Also the replacement of anhydrite by P-gypsum (DD 113-201) or by waste products of dry flue gas desulfurization (DD 241891) or by P-gypsum and de-gas desulfurization products OE 3622688) is known. Also known is a process by which SO ₂ from waste sulfuric acid and acid is recovered by feeding the reaction mixture formed by combining the components into the rotary kiln of the gypsum-sulfuric acid process so that the SO 2 concentration of the furnace gases can be improved ( DD 260616). Numerous processes for the desulphurization of flue gases have become known in which waste products (REA) of different composition are obtained, which can only be used economically in part. In particular, in spray absorption process' SAV) arise CaSOj-haltlge waste products, which find no use according to the current state of the art and must be deposited costly (ZKG 11/88, pp 576-582). Depending on the method involved, these waste products can be loaded before or after a dedusting plant with or without ash. Aim of the invention The aim of the invention is to develop a process for the production in cement clinker and for the recovery of sulfur dioxide, which takes place with reduced total expenditure in the gypsum-sulfuric acid process using hitherto presumably utilizable waste products. Explanation of the essence of the invention The object of the invention is to replace natural anhydrite in the gypsum sulfuric acid process as CaO and SOj carrier so by waste products that high quality cement clinker and SO ₂ -containing gases for the conversion to SO ₃ can be produced. According to the invention, this object is achieved in that in the gypsum sulfuric acid process a clinker raw meal mixture is used, which contains "as anhydrite substitute CaSOj-containing waste products from flue gas desulfurization as CaO and SOj carrier in Anteiion of 5 to 80% and this raw meal mixture in the rotary kiln inlet region with waste sulfuric acid in the molar ratio H ₂ SO 4 CaSO _{3 is} sprayed from 0.2 to 1.0, As CaSOj-containing waste products are REA-Produkto with 21 to 80% CaSO ₃ and 5 to 20% CaSO ₄ , as waste sulfuric acid, an acid with 78 to 100% H ₂ SO _4. An advantage of the method according to the invention, in which high-quality cement clinker are obtained, consists in a reduced total energy expenditure for the stages of raw-milk production and the firing process on SO ₂ in the REA product compared to gypsum by waste sulfuric acid at least equalized and thus gases higher SO ₂ content obtained in existing Systems can be converted to SO ₃ with reduced energy consumption. The process uses waste materials containing CaSO ₃ and waste sulfuric acids free of wastes. Ausführungsboisplel To compare the process according to the invention with the crude mixture known hitherto, cement clinker and SO 2 -containing gases are produced by metering in waste sulfuric acid from the following crude mixtures: