DD210167A3 - PROCESS FOR THE PREPARATION OF FULL MOLECULAR FORMULAS FOR CALCIUM CARBIDE GENERATION - Google Patents

Abstract

The invention relates to a process for the preparation of Vollmoellerformlingen for the CaC deep 2 generation with the required stoichiometric CaO / C ratio after a one-stage pyrolysis. According to the invention this is achieved by starting from natural limestone and coal and these primary raw materials are preferably mixed with small amounts of auxiliaries. After a common grinding to high fineness, a pre-compression of the ground material and a high-pressure briquetting the kleinstueckigen briquettes are gently degassed to 1000 degrees Celsius, and cooled dry.

Description

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Title of invention?

Process for the preparation of full-fat molds for calcium carbide production

Field of application of the invention:

With the method according to the invention, special briquettes are produced from primary raw materials, from which a high-quality lumpy Vollmöller- can be produced by the one-stage pyrolysis * The Vollmöller contains all raw materials for the chemical 'process of calcium carbide production in the required stoichiometric ratio .. Sr / ~ \ stands out due to high strength and ideal reaction behavior. The full-size moldings are used in the calcium carbide industry.

Characteristic of the known technical solutions;

For the production of calcium carbide by the electrothermal process quicklime and coke in the stoichiometric ratio of about 60: 40 "is needed.In almost all production facilities, the Carbidöfen with a mixture of small lime and coke in the specified mass ratio, taking into account the inert materials contained in the raw materials as well as losses

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fed. Under the conditions mentioned, quicklime made from limestone and coke from suitable brown or hard coal are each produced in separate pyrolysis plants. However, when feeding the carbide furnace with a mixture of small-sized quick lime and coke, the rate of CaC2 formation reaction is low. In addition, this form of furnace charging causes high specific energy consumption and expense for the stocking and charging of the carbide furnaces. ,

It is already well known to overcome these drawbacks by providing a Yollmoeller for calcium carbide production. remove. The solid filler consists of the main partners CaO and coke in the required stoichiometric ratio and in a homogeneous composition. At the same time it is characterized by its high porosity, particularly favorable reaction behavior and high electrical resistivity. This prior art is z. B. in SIRISBBL in "requirements, the calcium carbide oven to Köksqualität ^u , Freesberger Berger research booklets A. 140 - 1S60, described". Furthermore is. a method for producing a Yollmöllers from KaJLk coke briquettes known in the fine-grained quicklime and fine cokes mixed with 20 to 30 % of a suitable Bindemitteis the tar or petroleum processing and under optimal.Brikettierbedingungen to. small-sized compacts are pressed. In addition, a Hachverkokung the Binderpreßlinge · This 'method', which was described by RAMMLTSR and KOHL in "studies for! Rage the production and use of lime-coke briquettes in the Calaium Garbidindustrie", Freiberger Research Bulletins A 364 1966 described , thus distinguishes itself by the

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Disadvantage of the fact that high quality and expensive binders from the field of coal or petroleum processing are required for its implementation · In addition, the binder compacts alone for the purpose of thermal stabilization and aborting of the volatile constituents of the binder prior to use in the Carbidöfen with a high process outlay one Although the briquettes consist mainly of CaO and fine coke, which have already been refined by a high temperature analysis.

Fach DD-PS 123185 and KRUG, TEOMMSES and NAUNDOHP in. "Production of lime / coke briquettes for processes with." high heating rates ", Freiberger- Forschungshefte A 580 - 1977, KalS / Koks briquettes can be 'also produced without the use of binders' when the lime ia form of slaked lime milled together with the coke to high fineness and then the millbase by high-pressure briquetting with ρ However, according to this process, thermostable compacts are produced only when the briquetting material is compressed with a moisture content of 10 to 15% and coke contents of 30 % . The process is thus distinguished by the disadvantage that after him no Vollinöller can be produced with the required stoichiometric CaO / C ratio

SO therefore still necessary. In addition, due to the high water content of these lime / coke briquettes, only small quantities may be used directly in the carbide furnaces. At higher rates of use, the lime / coke briquettes must be converted to anhydrous CaO / coke briquettes prior to their use in the carbide furnaces the briquetted coke has been previously treated by high temperature

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coking was refined.

The share of Peinkokses the slaked lime / coke briquettes can be increased beyond that mentioned in DD-PS 123185 limit of = · 30% if the slaked lime and fine coke mixed with sulfite liquor "are pressed · ens This currently also partially practiced traversing variant Due to the high water content of these briquettes as well as their volatile content, only small amounts can be used directly in the carbide furnace. ·· At higher rates of use, <aee slaked lime / coke / sulphite liquor briquettes must be separately postcrosslinked to the dyestuff furnaces prior to their use The increase in Hohstoffveredlung is low in this additional pyrolysis, because the briquetted coke has already been refined by coking.

· * · ^Η ED PS 139,948th production of Verbundkoks by the coking of Back-enabled coal with CaO or preferably slaked lime is proposed · The proportion of lime must in this process despite the use of bäckfähigen coal - ca · 15% do not exceed because Otherwise, the strength of the hard coal coke deteriorates rapidly · In addition, even in this method already thermally refined CaO or preferably Ca (OH) ₂ used · If one uses lignite with a moisture content ws 11 % and jsiner grain size of about 1 / Ö mm, may the admissible proportion of Ca (OH) ^ ^{in the} coking briquette is only 5 % . This was determined by KHUG and IAULHX) EF in co-coke from non-coalified or low-pitch coal or lignite ", Freiberg Forschungshefte A 635-1980. "

Thus, according to the current state of knowledge, lime and coal can not be used to produce a solid composite coke which can produce the reactances CaO and C in the required stoichiometric state.

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contains metric ratio. Nothing will change in this situation, even if the proportion of Ca (OH) o in the briquetting material can be increased to a maximum of 20 % by a slurry digestion process. In addition to this, wet digestion milling requires an extremely high process-technical effort. "

Aim of the invention;

s ~ "The aim of the invention is a method for producing *" - '130 Vollmöllerfcrmlingen for Calziumcarbidindustrie with the required stoichiometric CaO / coke ratio for a single-stage pyrolysis, which are distinguished by high strength and ideal responsiveness ·

presentation; the essence of the invention:

^It is an object of the present invention to provide a process for producing high performance and high performance volumetric briquettes for the calcium carbide industry by the one-step pyrolysis process having (~) that described above sufficiently well-known in the art and its products Disadvantages are avoided »

According to the invention, the object is achieved by the fact that, in the course of the process, the primary raw materials are natural limestone and coal in the form of non-or very low-baking hard coal or brown coal, to which small quantities of auxiliaries are added coal is taking into account the different content of volatile components of the respective type of coal, the C-Gehai- tea of the excipients and the partial gasification of

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Carbon adjusted so that, the required GaO / G ratio of about 60: 40 during pyrolysis sets * The mass ratio of limestone and coal varies usually between 60: 40 to 40: 60. By using the Faturkalksteines is achieved that its relatively high natural briquetting and lump formation capacity contributes to the formation of a stable poultry molding association. ♦ As a source of raw materials, especially in the lime works often -v 150 is only insufficiently utilized, partially recovered. fine-grained limestone can be used. Likewise, the use of the C-containing raw material in the form of stone or lignite makes it possible for the sometimes very high briquetting and coke-forming capacity of the coals to also contribute to the formation of a solid full-grain association. As adjuvants are products such. B ,. Sulfite waste liquor or slaked lime, which are characterized by favorable briquetting and pyrolysis properties, and at the same time act on the limestone and the coal so that the individual contributions of the commodity contributors to the formation of a solid all-wool association appear more than sumo but only achieved if all three raw material components limestone, coal and auxiliary material are comminuted together in the necessary mass ratio and in this grinding a grain size of Ad = 0.2 / 0 mm is achieved · It is also crucial for the formation of a solid Vollmöllerverbandes that the after milling finely dispersed and homogeneous, mixed components of the drilling material are transferred into a state of highest solids aggregation,

before and during the pyrolysis, the conversion reactions can take place in such a way that a solid Vollmöllerverband forms · The high solids aggregation is achieved by the pulverulent and very flowable millbase first with a specific compression pressure of about 30 to 60 MPa precompressed and by gentle breaking converted into a secondary grain size of about 6/0 mm

- ν - 2 3 A 7 b U t)

Will »Each, del? Pre-compaction is the Brikettiergut by. High pressure briquetting depending on the type of coal used at a compression temperature of 40 to 100 " ⁰ C, preferably at 80 ⁰ C, and an EreJa- pressure of ρ =" 100 L ¹ IPa, preferably ρ = I50 MPa, pressed · In addition It is crucial for the success of the process that the limestone and coal are processed with a moisture content of preferably > 2%, and lignite with a moisture content of > 12%, preferably 1 * 9%. Furthermore, it is advantageous-W. liable, especially when using sulfite waste liquor as an excipient, either by heating during mixing or in connection with visual processes during grinding or during transport, for example. Be evaporated 1/3 of the introduced by the excipient water so that on the grain surfaces of the coal and limestone particles, a slightly "dried" film of the excipient.

The Brikettiergut is to be compacted to small compacts, because small-sized compacts, for example, on molding. trough roller presses can be pressed so that the required high solids aggregation is achieved even in the interior of the molding · At the same time smaller, 2TO lumped compacts are less by pyrolysis gases and vapors. weakened »Furthermore, solid VoIlmollerformlinge arise only if the high-pressure briquettes are subjected to a high-temperature degassing during pyrolysis after the respective coal-specific, gentle Aufheizregime. When coal is used, the average heating rate is preferably 10 k min . When using 3-lignite coal, the compacts become even more gentle, eg after the heating-up regime of

YOLIMAIES, with 0.83 K. min " to 320 ⁰ C and with

-1

2,8'K-. degassed to the final temperature of the high-temperature degassing. The cooling of the Yollmöllerformlinge takes place dry. , '

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Moreover, the inventive method can also with the use of calcium hydroxide, / Ga (OH) ₂ ..?, Z. B. obtained in the carbide industry as by-product, or calcium oxide (GaO) are performed ·

The transport and storage of the full-size moldings produced according to the invention must take place in closed trees in order to avoid a conversion of the calcium hydroxide into calcium hydroxide with the associated destruction of the moldings.

By applying the above patent invention, high economic gate parts are involved, which relate both to the broadening of the source of raw material as well as the production of the carburetor. As a result of the method according to the invention a Möller is produced with high strength and high electrical resistance with intimate contact of the Beaktionspartner, whereby in the Garbiderzeugung a significant increase in the reaction rate and the furnace throughput is achieved with decreasing specific electrical energy consumption. The occurrence of disturbances due to false grain formation is avoided. These effects in: Users can be achieved, nevertheless for the production partially less valued starting or »waste products, such as lignite, non-baking hard coal, fine lime and sulfite waste liquor are used. Since the pyrolysis of coal and limestone takes place in one operation, the costly separate preparation of raw materials can be omitted at the same time. This will

25Ö generation of a new low-cost raw material associated with the improvement of the application conditions compared to the current state of the art.

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Embodiment:

The erfindungsgeraäße method will be explained in more detail below by means of four embodiments.

1st example

Natural limestone with a moisture content of w = 1.1% and low-baking type 33 coal with w = 2.1% in a mass ratio of -60: 40 with 5 % G-crude oil (dried sulphite liquor) and. Then, with a ball mill to a grain size of Δ d = 0.18 / 0 mm smaller t * The millbase is 'with a pressing pressure of ρ ss 40 MPa ' z * 3. on a roll press to about 10 mm thick films thickened, the immediately crushed to a grain size of Δ d ^ 8/0 mm · The precompressed Brikettiergut is ρ = 70 ⁰ G and a pressing pressure of ρ = I50 to small-sized MPa and well durchpreßten formations pressed by Hbchdruckbrikettierung with a Verpressungsteaperatur of / "· From the high pressure briquettes

27Ο are formed by gentle degassing up to a degassing end temperature of ^ g _n -J; = 1000 ⁰ C with an average heating rate of 2 K. min "after w subsequent dry cooling Tollmöllerformlinge with the following quality parameters:

, CaO / C ratio 61/39

Compressive strength of the Voil-

Möllerformlinge 'ν, = 20.7 MPa

Abrasion resistance of the voucher molds after 300 revolutions of the IfB drum E3O (3OO) = 86.1 %

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2nd example

Natural limestone with a moisture content of w = 1.1 % and low-baking hard coal of type 33 with w = "2.1% are mixed in a mass ratio of 57: 43 without the addition of auxiliaries and with a vibrating mill to a grain size of Δ d = 0, 12/0 mm crushed · This millbase is compacted on a roll press to form sheets about 10 mm thick with a pressure of ρ = 40 IiIPa, which are immediately crushed to a secondary grain size of Ad ~ 5/0 mm. ^ ^ 290 The precompressed briquetting material is a Yerpressungstemperatur of / ^ p = SO ⁰ C. and a pressure of ρ = 200 MPa. small-sized high-pressure briquette pressed · created from the Hochdruckpreßlingsn by degassing to a Entgasungsendtemperatür from / fr -g = 1000% with an average heating rate of 1.6 K min. and, after subsequent dry cooling, Yollmö moldings with the following quality parameter η:

CaO / C ratio 59/41

Compressive strength of the filler moldings ^ k = ²⁰⁾ 5 ^iIPa

'' Ability of the Yo ll

Moldings after 300 revolutions IfB-Troimnel E30 (3.00) = 84.0%

3 *. example

limestone with a moisture content of w = 1.1 % and dry lignite with w = 9.1% are mixed in a mass ratio of 50: 50 with 20 % sulfite waste liquor at a mixed product temperature of about 70 ⁰ G and then with a vibrating mill to a grain size of Ad = 0.12 / 0 mm crushed. The material to be ground is pressed with a pressure of.

ρ = 50 MPa 'on a roll press about 10 mm thick

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Compacted films, which are now crushed to a grain size of Δά = 5/0 now. This pre-compressed Brikettiergut is pressed with a terpressive temperature of / ^ p = 80 ⁰ C and a pressure of ρ = I50 Ii ¹ IPa to small-sized high-pressure briquettes. From the "high pressure" briquettes are formed by gentle degassing after the heating regime of YOLIMAISR _o up to a degassing end

temperature of λ / --- '= 1000 % and after a dry cooling Tollmollerforsilinge with the following quality parameters:

CaO / C ratio 62/38

Compressive strength of the Toile

Möllerformlinge (T ^. = 12.2 L-IPa

Abrasion resistance of oil moldings according to

300 Ttadr. the IfB drum E3O (3OO) = 65.2%

4 »Example

Natural limestone with a moisture content of w = 1.1 % and dry lignite with w = 9> 1% are mixed in a mass ratio of 45:55 with 10 % slaked lime and 10 % green pellet as auxiliary material and subsequently with a vibrating mill to a grain size crushed by Δ d - 0.12 / 0 mm. The regrind is with a. Pressing pressure of ρ = 40 MPa compressed on a roll press to about 10 mm thick films, the immediately ^au; for a grain size of Λ d = 5/0 mm. The precompressed Brikettiergut is pressed with a terpressing temperature of ^ l = 80 ⁰ C and a pressure of ρ = 180 MPa to small-sized high-pressure briquettes. From the high-pressure briquettes are formed by gentle degassing after the heating regime of TOLBiAISE up to a final gas temperature of A / ^ _{n +} . "= -1000 ⁰ G and after a dry cooling Tollmöllerformlihge with the following quality parameters:

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CaO / C ratio 61/39

Compressive strength of the Youll

Möllerformlinge V. = 17.2 MPa

Abrasion resistance of the YoYl

Let the molds follow.

300 meters the IfB-drum E3O (3üO) = S1,2 %

Claims (4)

Erf indungsans pruch 1. A process for the preparation of Vollmöllerformlingen for calcium carbide production, characterized in that calcium hydroxide / Ca (OH) ₂ _7oder calcium oxide (CaO), preferably limestone, with a moisture content w <10% and hard coal or lignite with a moisture content depending on the respective raw material a depending on the nature of the raw material components used stoichiometric ratio both with and without the addition of excipients to a 36 o high fineness of 0.5 / 0 mm, preferably from 0.15 / 0 mm are comminuted and from the pulverf'drmigen regrind by pre-compression with a pressure of about 30 to 60MIa and then gentle comminution a secondary grain size of about 8/0 is prepared by high pressure briquetting with a compression temperature of 40 to 100 ⁰ Q preferably 80 ⁰ C, and pressing pressures of ρ ^ 100 MPa, preferably 150 MPa, compacted into compacts with a very high solids aggregation and the special briquettes by one of the Depending on the raw materials dependent gentle high temperature pyrolysis degassed and then cooled dry. 2. The method according to item 1, characterized in that the use of hard coal whose moisture content is preferably wv2% and the average heating rate up to the gasification temperature * ^ 1OK.min- -1 ' preferably 1 to 2 K, min. 3. The method nach.Punkt 1, characterized in that no ι ii u λ η ο ο ^ / γ λ 23476 when using lignite whose Peuchtegehait preferably w - 8 to 10% and the average heating up to the degassing temperature of about 320 ⁰ C, preferably 0.83 K.min "* and up to Entgasungsendtemperatur preferably 2.8 K, min. 4. The method according to item 1 to 3, characterized in that are used to secure a high Yollmöllerqualität as auxiliaries preferably sulfite waste liquor with a solids content of about 55% or dried to powder sulfide liquors.