DE2302009B2 - METHOD FOR MANUFACTURING PORTLAND CEMENT CLINKERS - Google Patents

Description

2. The method according to claim 1, characterized by reacting calcium aluminate and calcium aluminate ferrite, that one yaws 20 by wet grinding.

crushed and the slag snd the fine pulp to promote the conversions when burning is

the remaining raw materials. it is customary to first wet the raw materials used

3. The method according to claim 1 or 2, thereby or dry finely ground, expediently so far, characterized that the mixing of that not over 10%> of the raw material mixture a pound sand with the other raw materials only have a grain size of more than 200 microns. Often this will be in the kiln. entire material to be introduced into the furnace, e.g. B. on a

4. The method according to any one of claims 1 ground mean grain size below 65 microns. Man to 3, characterized in that the fine grinding of the entire furnace material was considered to be little at least 2 percent by weight of blast furnace slag, necessary to ensure the best possible mixing of the gene on the dry matter of the kiln, 3 ° components to receive and thus a complete clean, to enable action in the oven. The entire raw

5. The method according to any one of claims 1 mixture of substances was then obtained in the form of to 4, characterized in that there is little fine meal or fine sludge gestens in the sintering furnace 5 percent by weight of blast furnace slag.

moved to the dry matter of the kiln, 35 It is also known as one of the raw

begins. to use materials for the furnace material blast furnace slag.

6. Use of the product after the blast furnace slag is usually as slag sand. Process according to claims 1 to 5 for the production of Portland cement, blast furnace Hch, the composition is usually 28 cement, trass cement or trass blast furnace cement with a particle size of at most 5 mm . 40 to 38 "/ 0 SiO ₂ , 9 to 18" / 0 Al ₂ O ₃ , 0 to 3% Fe ₂ O ₃ and

35 to 48% CaO. Blast furnace slag thus contains too for the production of Portland cement clinker little CaO and can only be used if

CaO or a CaO former is added.

45 If blast furnace slag was previously incorporated into the furnace material, this was done after dry grinding of the mixture to the small particle size customary for the oven material. A wet grinding

The invention relates to a method for the production of blast furnace slag with lime or lime formers The development of Portland cement clinker from a 50 does not lead to useful results because Usual gross composition of the initial compound blast furnace slag, latent hydraulic properties fertilize resulting mixture of raw materials, which is under possession. It reacts with water in the presence of one other lime and / or a lime former and high activator, such as lime, gypsum or Portland cement. A Furnace slag contains, by crushing and mixing, a water-containing mixture from ground blast furnace Raw materials and burning of the raw material mixture 55 slag with lime or lime formers partially hardens at least 1350 ° C. or completely off, so that such a mixture does not

Processes of the type specified above can be worked up in the usual way, even then, well known and practiced on a large scale when only a small amount of ground blast furnaces are used. The cement clinker becomes after slag is present. This is not just because of the Cooling and grinding, the latter often together 60 premature setting and the resulting with a small amount of plaster of paris to delay setting, difficulties in mechanical processing gerer, portland cement received. The grinding becomes disadvantageous, but also because of the additional also together with blast furnace slag in a fuel consumption that the removal of the when Amount up to 85%, based on the sum of the setting of bound water during burning in the Clinker and slag, required for the production of blast furnace 65 furnace.

cement and / or together with trass to produce Another known method, blast furnace slag

carried introduce into the sintering furnace of trass cement or Traßhochofenzement, is the ^{fl "lfirt} dust finely ground slag, optionally together

3 4

men with cement kiln dust into which the rotary kiln grind. The setting time of the gypsum slag cement

atomizing heating flame. This is not determined by the choice of the slag grain size, but rather

Slag melted, the melt particles being controlled by the choice of the anhydrite grain size

Considerable amounts of heat from the flame on the slag are in all cases ground so finely that

Transfer oven content. 5 not more than a very small amount, e.g. not

In all of the above procedures, more than about 3 ^e / o, a grain size of over 90 microns, had to be finely divided into all of the raw materials introduced into the furnace. Such methods of operation can be invented, which is relatively high milling out of the question and entails craft costs. borrowed transfer to the manufacture of Portland

It is in the literature a very long time ago that io cement clinker is neither possible nor successful,
been specified (DT-PS 82 210 from the year The invention is based on the object of an 1895) to incorporate unmilled blast furnace slag into a furnace method of the type specified for Hergut. It is proposed there to create a position of Portland cement clinker, the kiln material from the usual raw materials in powder form does not have the above and similar defects and the usual composition to put together 15 of the known working methods, a faultless and this also a lot of unmilled free processing of Blast furnace slag makes it possible to add slag sand from blast furnace slag, which then sintering the use of blast furnace slag, even with wet mix, and then allowing the raw materials to cool down and allowing savings so that the usual hard cement does not result in the preparation of the furnace material,
clinker, but rather a crumbly, easily crushed ao object of the invention is for this purpose a method mass is obtained. This patent refers to the production of Portland cement clinker from the product of the shaft and one the usual gross composition of the outer ring kilns. According to the invention z. B. in a raw material mixture resulting in rotary connections, the product obtained is not crumbly due to the use of, inter alia, lime and / or a lime-forming mixture of unmilled blast furnace slag in which raw and blast furnace slag contains raw material mixture. According to today's knowledge and mixing of the raw materials and burner, the raw material, the crumb of the cement clinker according to the above stoffgemi ^ ches is at least 1350 ° C, which is not characterized by the properties or shape of the blast furnace, but rather an increased C ₂ S slag only after the crushing of the remaining Mi content (2 CaO · SiO ₂ ) and the slow cooling 30 as slag sand with one of the cement clinker, whereby this mean grain size of at least 0.2 mm as a result of the implementation from /? C _? S mixed in γ C ₂ S, connected.

with volume increase, can fall apart. Surprisingly, in the method of

This increased C., S content, however, has a reduction in the blast furnace slag despite the rather large

tion of the hydraulic properties of the cement - the grain size of the slag sand when burning

clinkers result. easily and completely implemented and an excellent

It is also known (essay by F. Köberich neter Klinker received, the usual in none

»Regarding the method of making plaster of paris, see below.

cement and new development opportunities «in the blast furnace slag in the form of the the magazine Zement-Kalk-Gips, 1949, p. 109 to 40 unmilled slag sand also processed wet 113, especially p. 109, right column, paragraph 3, and are. By putting them into a pulp of the finely ground P. 112, right column, paragraphs 4 and 5), in which other raw materials are mixed in without a The formation of gypsum slag cement with a fixed addition of setting is to be feared. There is no premature of Portland cement clinker at a rate of 5% for hydraulic hardening or lump formation, in hindrance of a setting reaction during processing. This is clearly in contrast to wet processing to partially dewater the gypsum and prevent mutually exclusive processes during mixing to use separate grinding process, with the dimensionally finely ground blast furnace slag with a fine input, that the plaster of paris is ground much finer pulp.

than the slag. It is also stated there that lime- The use of blast furnace slag as a slag rich Slag already with a coarse grinding of 50 sand with a mean grain size of at least 3.2% on the 4900 mesh screen, i.e.> 0.09 mm, 0.2 mm also brings considerable savings an extraordinarily high initial compressive strength in terms of operational effort and costs for the Mahvon Gypsum slag cement with only a few of the raw materials involved.

Percentages over 18% Al ₂ O ₃ yields. The application of blast furnace slag as raw material

thus a process for the production of 55 material for clinker production is additionally with a

Gypsum slag cement, in which blast furnace slag is associated with energy savings during firing, there

Plaster of paris and a little Klinket mixed, the mixture per blast furnace slag already a considerable amount

but not burned, d. H. contains a completely different amount of CaO and thus that of a number of others

Working method and a completely different product than required for raw materials, heat and thus fuel

the production of Portland cement or the burning of CaO ₁ to CaO for the

cement clinker. Furthermore, the slag is also there due to the CaO additive added by the blast furnace slag.

ground to a grain size in which part of the contact that is bound _{to SiO 2} and / or Al ₂ O _{3 is}

Setting with water and plaster takes place because so-is falls.

yes there would be no gypsum slag cement. It becomes slag sand with a medium grain wet processing is at least 0.2 mm in terms of ligature size and usually over times of gypsum slag cement not possible. Used at 0.5mm. The slag sand can be wet or The use of anhydrite is mixed with the other raw materials with separate mowing dry the anhydrite is somewhat coarser than the slag, the latter in the form of a

5 6

Fine pulp and in the dry process in the form of Fe ₂ O ₃ , 66.9%> CaO, 1.3% MgO (remainder 1.3%). That

Be repented of flour. The slag sand can also have a mixture of the following grain sizes:

introduced separately into the rotary kiln and only -> 200 microns 2%

'.'in are mixed with the other raw materials. -> qq microns 050 /

The reactions proceed in practically 5> 63 microns in all cases 40 ° /

the same way. _{> 32microns} ;;;;;;;;;;;;;;;;;;;; _5o " _{/ o}

As a starting matenanen door to the establishment of the

Portland cement clinkers can only be used if desired

the blast furnace slag sand brought in together with aggregate a rotary kiln and there during

substances such as limestone and pyrite ash, and in the 10 a residence time of about 150 minutes at a

desired content of CaO and possibly Fe ₂ O ₃ maximum temperature of about 1450 ° C. There-

to be used. One can, however, "use a clinker brick that is more common

in addition to any amount of other common raw grinding, an excellent Portland cement

Use materials such as ground slate, clay, mer- yielded.

gel and gypsum to form a mixture of the total composition desired for the example of the method of the invention, so that the mixture was made into a pulp in the same way, mixed with blast furnace slag sand and lime-forming agent limestone, SiO, artificial stone and pyrite ash only makes up part of the oven. It is clear, ground in the desired ratio in water, that the above-mentioned, achieved according to the invention were achieved. This fine pulp had the same grain size parts, the larger the more blast furnace slag ao as that of the comparative experiment. The chemical state is used. Preferably, therefore, the composition, based on loss-free material, was at least 2 percent by weight and particularly preferably: 17.3% SiO ₀ , 2.3% Al ₂ O ₃ , 3.1% Fe ₂ O ₃ , added at least 5 percent by weight blast furnace slag, 75.5% CaO, 1.3% MgO "(balance 0.5%).
Based on the dry matter of the kiln, 40 parts by weight of this fine pulp were used. Even with these relatively small furnace slag sand, based on the amount of Ge without loss of ignition, the advantages are clear. mixed, admittedly. The chemical composition

The clinker obtained according to the invention, including the slag sand, was: 34.3% SiO ₂ , 12.8%

In terms of composition and properties, Ai ₂ O ₃ , 2.2% Fe ₂ O ₃ , 41.8% CaO, 5.8% MgO (remainder

barely or not at all of the usual Portland 3.1%). The grains of the slag sand were

cement clinker. It can be just like in the well-known 30 as follows:

Well-preserved Portland cement clinker with the ^ -, _{A 50 /}

.. ,,. , _w / ι. ι τ- »■ '- ^> 2.4 mm j%

usual amounts of gypsum as a solidification inhibitor to ^, _o " _{m ano /}

r. ,, ^v ,, j -X, "v> 1.2 mm 30%

Portland cement are ground. He can also · _n & ", - <-",

by grinding and mixing with the usual additions- «^ _n - _{mm QJ} - _{0 /}

. ", U-JT * -> 0.2 mm 95%

Process substitutes for the various types of cement 35

be worked, z. B. to iron portland cement or the suspension thus formed showed on standing

Blast furnace cement due to dry grinding together - even after a few hours no signs of

men with gypsum and blast furnace slag, hydraulic hardening to trass cement and could in the same

or to blast furnace cement. The obtained pro-manner like the mixture of the comparative experiment in

In every respect, products are the same well-known and 40 the same rotary kiln as Portland cement clinker

significant. to be burned. The oven residence time was again about 150 minutes and the maximum temperature

Example with comparative experiment also around 1450 ° C. Also occurred in the oven during the drying of the wet applied mass

For the comparison test, a mixture 45 showed no signs of hydraulic hardening

Manufactured by adding limestone, an SiO ₂ artificial stone, Py or lump formation. After it was burned

ritasche and slate in the desired. Ratio of excellent clinker, which according to

mixed and ground in water to a fine sludge comparable to a Portland cement which

were grind. The chemical composition is not noticeable in terms of properties

this mixture, based on the mixture of the comparative experiment, which is free from ignition loss

material, was: 22.4% SiO ₂ , 5.3% Al ₂ O ₃ , 2.8% Portland cement difference.

Claims (1)

As is known, the gross composition of Fortiand cement clinker with regard to the various patent claims: Components should be approximately in the following limits: 61 to 69% CaO, 18 to 24% SiO2, 4 to 8% 5 AIgO3 + TiO2, 1 to 8 "VoFe2O3, low Amounts of 1. Process for the production of other Portland oxides. The properties of the end-product cement clinker from the usual gross charge are relatively independent of the composition of the starting compounds Components so lime and / or a lime-forming agent and blast furnace io react with one another as much as possible. Contains slag, by crushing and mixing the usual starting materials are calcium of the raw materials and burning of the raw material carbonate in the form of limestone or marl mixture at at least 1350 ° C, resulting in (CaCO ₃ + clay), clay or slate, the SiO ₂ , AI, O ₃ indicates that they contain the blast furnace and mostly some Fe ₂ O ₃ , and iron-containing slag only after the other 15 aggregates have been crushed, such as pyrite ash or iron ore. The mixture constituent as slag sand with calcium carbonate is decomposed during firing to CaO, an average grain size of at least 0.2 mm which is mixed with the other components to form the. wanted tricalcium silicate, dicalcium silicate, tri