CH335989A

CH335989A - Cement manufacturing process

Info

Publication number: CH335989A
Authority: CH
Inventors: Elie Doumet Michel
Original assignee: Elie Doumet Michel
Priority date: 1956-06-02
Filing date: 1956-11-19
Publication date: 1959-01-31

Description

Proce'de' de fabrieation de ehnent Deux proc#d#s principaux de production de ci- ment sont connus. L'un est appeM proc6d6 par voie humide et Fautre, par voie Sache. La fabrication proprement dite du ciment est obtenue par la cuisson ä haute temp6rature d'un m6lange de certaines ma- ti#res premi#res, consistant habituellement en un m61ange de mati#res argileuses et calcaires dans un four, ä une temp6rature suffisante pour que les ma- ti#res se vitrifient. La masse vitrifi & est alors broy6e en poudre fine et m61ang6e ä d'autres mati#res, telles que le gypse, pour obtenir le ciment Portland. Process for the manufacture of cement Two main processes for the production of cement are known. One is called wet process and the other is called dry process. The actual manufacture of cement is obtained by firing ä at high temperature a mixture of certain raw materials, usually consisting of a mixture of clay and limestone materials in a oven, ä a temperature sufficient for the materials to vitrify. The vitrified mass is then ground into a fine powder and mixed ä with other materials, such as gypsum, to obtain Portland cement.

Le type des mati#res argileuses et calcaires d6- termine le choix entre les voies humide et Sache. Selon le proc6d6 ä voie Sache, les mati#res sont s & cMes, si n6cessaire, avant le broyage ; on les broie ensuite ensemble pour obtenir une poudre fine et on les agite pour obtenir un m61ange homogene. Cette poudre est introduite dans le four, pratique- ment sans eau. Dans certains cas, les mati#res sont granuMes par l'addition d7une petite quantit6 d'eau avant leur introduction dans le four. The type of clayey and calcareous materials determines the choice between the wet and dry processes. According to the ä process, the materials are dried, if necessary, before grinding ; they are then ground together to obtain a fine powder and stir to obtain a homogeneous mixture. This powder is introduced into the oven, practically without water. In some cases, the materials are granulated by adding a small amount of water before entering the kiln.

Selon le proc6d6 par voie humide, les mati#res sont broy6es en particules fines pour former une liqueur d'eau et sont m61ang6es entre elles en pro- portions correctes. Cette liqueur, appeke bouillie, est alors soigneusement analys6e, corrig6e et homog6- n6is & dans des silos sp6eiaux ; on la verse ensuite dans une tr6mie qui alimente le four de cuisson. 11 est habituel d'introduire la bouillie dans le four, alors qu'elle contient de35 ä55 0/0 d'eau et parfois m8me 60 % d'eau. La proportion de Feau dans la bouillie est d#termin6e selon la nature des matii-Ires premi#res, qui doivent avoir une certaine fluidit6 pour permettre le mouvement de la bouillie dans les pompes, les dis- positifs m6caniques de manutention, les broyeurs, les silos de correction et d'homog#n#isation, etc. 11 est tr#s difficile de faire varier la viscosit6 par un moyen autre que Faddition de Feau. Une grande teneur en eau de la bouillie r6duit la capacit6 du four ; Feau y pr6sente doit 8tre 6vapor6e (ce qui consomme du combustible) avant que la mati#he ne commence ä se vitrifier. In the wet process, the materials are ground into fine particles to form a water liquor and are mixed together in the correct proportions. This liquor, called boiled, is then carefully analysed, corrected and homogenized & in special silos ; it is then poured into a hopper which feeds the cooking oven. 11 it is customary to introduce the porridge into the oven, while it contains from35 to55 0/0 of water and sometimes even 60 % water. The proportion of water in the slurry is determined according to the nature of the raw materials, which must have a certain fluidity to allow the movement of the slurry in the pumps, the mechanical handling devices, the grinders, correction and homogenization silos, etc. 11 is very difficult to vary the viscosity by any means other than the addition of water. A high water content in the slurry reduces the capacity of the kiln; The water y present must be evaporated (which consumes fuel) before the material starts B>ä to vitrify.

L'avantage du proc6d6 par voie humide est qu'il assure un m61ange meilleur et plus homogene des ma- ti#res argileuses et calcaires et donne souvent lieu ä un meilleur ciment. En outre les mati#res premi#res, en particulier celles du type ealcaire, se pr8tent sou- vent mieux au broyage fin et au m61ange avec les autres mati#res en prAence de Feau. Apr#s que la poudre et la bouilhe ont 6t6 introduites dans le four pour la cuisson, les deux proc6d6s sont sensiblement identiques. The advantage of the wet process is that it provides better and more homogeneous mixing of clay and limestone materials and often results in better cement. Furthermore, the raw materials, in particular those of the limestone type, often lend themselves better to fine grinding and to mixing with other materials in the presence of water. After the powder and slurry have been introduced into the oven for cooking, the two processes are substantially identical.

La pr6sente invention concerne un proc6d6 de fabrication de eiment qui comprend les op6rations consistant ä combiner une bouillie obtenue selon le proc6d6 par voie humide, avec une poudre obtenue selon le proc6d6 par voie Sache pour former un m6- lange de mati#res, avant leur introduction dans un four de cuisson, ayant une teneur en eau comprise entre10 et35 %. Les mati#res argileuses et calcai- res pr6par6es selon le proc6d6 par voie Sache peu- vent etre avantageusement introduites dans une tr6- mie d'emmagasinage. Semblablement, une bouillie argileuse et calcaire pr6par6c selon le proc6d6 par voie humide peut etre introduite dans une tr6mie d'emmagasinage. Une tr6mie, qui alünente directe- ment le four de cuisson, peut Ure aliinent6e direc- tement par la tr6mie ä poudre et la tr6n-iie ä bouillie, des dispositifs 6tant pr6vus pour r6gler les propor- tions relatives de bouillie et de poudre dans la tr6- mie. Un dispositif est de pr#f6rence pr6vu pour m61anger de mani#re convenable la poudre ä la bouillie avant leur introduction dans la tr#mie d'ali- mentation du four de cuisson. La teneur en eau des mati & es m61angdes, destin6es ä Ure introduites dans le four, peut varier comme on le d#sire, pour 6viter la formation d'anneaux dans le four. Ces anneaux sont formA de mati#res s#cMes qui collent aux parois du four, ce qui rend irr6guli#re la mar- che du four. Les anneaux g8nent Favance de la mati#re pendant un certain temps et, brusquement, laissent tomber une avalanche de mati#re lorsque Fanneau se brise. Le d#savantage est celui de la marche irr6,-uli#re du four et de la mauvaise qualit6 de la masse vitrifi#e produite, du fait des mouve- ments brusques de mati#re, ayant lieu ä cause de la vitrification insuffisante. The present invention relates to a process for manufacturing cement which comprises the operations consisting ä combining a slurry obtained by the wet process, with a powder obtained by the Sache process to form a mixture of materials, before their introduction into a baking oven, having a water content between10 and35%. The clayey and calcareous materials prepared according to the Sache process can advantageously be introduced into a storage hopper. Similarly, a clay and limestone slurry prepared by the wet process can be fed into a storage hopper. A hopper, which feeds the baking oven directly, can be fed directly by the ä powder hopper and the slurry ä hopper, devices being provided to adjust the relative proportions of slurry and powder in the hopper. A device is preferably provided for suitably mixing the powder to the slurry before they are introduced into the feed hopper of the baking oven. The water content of the mixed materials, intended ä Ure introduced into the furnace, can be varied as desired, to avoid the formation of rings > in the oven. These rings are made of dry materials which stick to the walls of the oven, which makes the operation of the oven irregular. The rings impede the advance of matter for a time and suddenly drop an avalanche of matter when the ring breaks. The disadvantage is that of the irregular operation of the kiln and the poor quality of the vitrified mass produced, due to the sudden movements of material, taking place ä due to insufficient vitrification.

La Präsente invention concerne aussi un appa- reil pour la mise en ecuvre du proc6d6 de fabrication de ciment. The present invention also relates to an apparatus for carrying out the cement manufacturing process.

Une forine d'ex6cution de Pappareil selon Pin- vention est dkrite ci-apr#s ä titre d'exemple en r6f6- rence aux dessins annex#s. An embodiment of the apparatus according to the invention is described below ä by way of example with reference to the accompanying drawings.

La fig. 1 est une 616vation lat6rale de l'appareil. La fig. 2 est une 616vation frontale de l'appareil C de la fig. 1. C, On fait usage d'une tr6mie 2 pour la bouillie pr6- par6e selon le proc6d6 par voie humide de produc- tion du ciment et une tr6mie 3 pour l'emmagasinage de la poudre pr6par6e selon le proc6d6 par voie Sache de production du ciment. La tr6mie 2 alimente un m61an-eur 1 par FintermMiaire d'un r6gulateur et la tr6mie 3 alimente le m61angeur 1 par Vinterm6- diaire d'une vis transporteuse 4. La vitesse de rota- tion de la vis transpQrteuse 4 est r6glable, de ma- ni#re que la quantit6 de poudre passant de la tr6mie 3 au m61angeur 1 puisse #tre, r#gIde. Dans le m61an- creur 1, un dispositif peut 8tre pr6vu pour agiter et m#Iang-.r la bouillie et la poudre en un m61ange sen- siblement homogene. fig. 1 is a side elevation of the aircraft. fig. 2 is a frontal elevation of the apparatus C of fig. 1. C, A hopper 2 is used for the slurry prepared by the wet method of cement production and a hopper 3 for the slurry. the storage of the powder prepared according to the process by the Sache way of production of cement. Hopper 2 feeds mixer 1 through the end of a regulator and hopper 3 feeds mixer 1 through the intermediate of a regulator. a conveyor screw 4. The speed of rotation of the conveyor screw 4 is adjustable, so that the quantity of powder passing from the hopper 3 to the mixer 1 may #be, r#gIde. In the mixer 1, a device may be provided for agitating and mixing the slurry and the powder into a substantially homogeneous mixture.

La sortie du m61angeur 1 conduit ä un four de cuisson 5 selon les proc#d6s connus de fabrication du ciment. The output of the mixer 1 leads ä to a firing kiln 5 according to the known methods of the manufacture of cement .

Avantageusement, la poudre contenue dans la tr6mie 3 est sensiblement d6pourvue d'humidit6, tandis que la bouillie contenue dans la tr#mie 2 con- tient 35 ä55 0/0 en poids d'humidit#. La quantit# de poudre m61ang6e ä la bouillie peut & re modifie'e, en r6glant la vitesse de rotation de la vis RTI ID="0002.0279" WI="14" HE="4" LX="946" LY="2168"> transpor- teuse 4, de mani#re que la teneur en humidit# soit d6termin6e d'apr#s la nature des mati#res argileuses et calcaires contenues dans la bouillie et dans la pou- dre et leurs compositions relatives. Cette teneur est d6termin6e aussi par le type du four et varie entre 10 et35 %. Advantageously, the powder contained in the hopper 3 is substantially devoid of moisture, while the slurry contained in the hopper 2 contains 35 to55 0/0 in moisture weight#. The amount of powder mixed to the mixture can be modified by adjusting the rotation speed of the screw RTI ID="0002.0279" WI="14" HE="4" LX= "946" LY="2168"> conveyor 4, so that the moisture content is determined according to the nature of the clayey and calcareous matter contained in the slurry and in the powder and their relative compositions. This content is also determined by the type of kiln and varies between 10 and 35%.

11 faut observer qu'en m61angeant la poudre pr6- par6e par le proc6d6 par voie Sache avec la bouillie pr6parde par voie humide, on introduit dans le four un m61ange homogene de mati#res argileuses et cal- caires, tandis que la proportion d'eau ä #vaporer des mati#res apr#s introduction dans le four est sen- siblement r6duite, ce qui r#duit les pertes de cha- leur et augmente le rendement du processus. 11 It should be noted that by mixing the powder prepared by the Sache process with the slurry prepared by the wet process, a homogeneous mixture of clayey and calcareous materials is introduced into the kiln. , while the proportion of water ä #evaporating materials after introduction into the furnace is significantly reduced, which reduces heat loss and increases yield of the process.

La pr6sente invention est aussi utile aux usines ä ciment oü les propri#t#s physiques des mati#res pre- mi#res venant des carri#res varient, ce qui donne lieu ä la formation de bouillies de teneurs en eau variant dans le temps. The present invention is also useful in ä cement plants where the physical properties of the raw materials from the quarries vary, resulting in ä the formation of slurries with water contents varying over time.

La pr6sente invention contribue ä la pr#paration de mati#res de teneur en eau reguliere pour Fali- mentation du four et assure-une progression r#gu- h#re dans le four et une cuisson r6,-uli#re. The present invention aids in the preparation of materials of even water content for kiln feed and ensures smooth kiln progression and rapid cooking. ,-uli#re.

Claims

CLAIMS : I. Process for manufacturing cement, which comprises the operations consisting ä of combining a slurry prepared by the process by moist with a powder prepared by the skhe process to form a mixture of the materials, before their introduction into a baking oven, having a water content of between10 and35 0/9. II. Apparatus for implementing the process according to claim 1, characterized in that it comprises a hopper for the mixture prepared by the wet process, a hopper for the powder prepared by the skhe process, a device for feeding a mixer ä from the hopper sets, and a device for feeding a baking oven, ä B> from m2ang--ur, in mixed materials. SUB-CLAIMS : 1. Process according to claim 1, characterized in that the powder obtained by the process by the Sache route the porridge is added ä suddenly before it is introduced into an oven for cooking.

2. Process according to claim 1, characterized in that the porridge and the powder are stirred before being introduced into an oven for cooking, to obtain a sufficiently homogeneous humidity. 3. Process according to claim 1, characterized in that the slurry is introduced from a storage hopper into a mixer and the powder is introduced from a storage hopper. stored in the mixer by an adjustable feeder to produce the desired proportions of powder and slurry, and the mixed powder and slurry are fed into an oven to the cooking. 4. Apparatus according to claim II. characterized in that it comprises a device making it possible to modify the proportion of the mixture to the powder introduced into the mixer.