RU2348587C2 - Method of obtaining lime - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method of obtaining lime involves limestone production in a quarry by open-air method, the limestone including, wt %: CaCO₃ over 91-92, MgCO₃ 5, S 0.058-0.06, P under 0.1, Al₂O₃+Fe₂O₃ 2.5-2.8. Limestone of 120-200 mm fraction is ground by dropping spherical loads onto it in cascades or 'waterfall' pattern, sorted in 3-11, 12-24 and 25-40 mm fractions, and limestone humidity is evaluated at 15-25%. Solid fuel is selected and delivered from storehouse. Dust particles of material to be ground are fed to dust collector through coaxial holes along rotation axis of mill rotation drum. Limestone and solid fuel are dosed by weight, fuel fractions under 20 mm are removed. Obtained charge is dosed by weight with simultaneous magnetic control of metal inclusion presence and removal of such inclusions. Charge is fed to rotating furnace where it is mixed with CO₂ and burned at 450-1000°C for 4-5 minutes. Obtained lump lime of 8-30 mm fraction is discharged, the lime containing, wt %: main active substances CaO+MgO 86-88, CO₂ 3-5.

EFFECT: enhanced manufacturability and environmental safety of method, possible control of source and target product processing, reduced decarbonisation of limestone.

1 ex

Description

The invention relates to the construction industry and can be used to create components of building materials of economic interest to small entrepreneurs and legal entities in the search for modern technologies in construction.

Known analogue of the book: Volzhensky A.V., Mineral binders: Textbook. For universities. - 4th ed., Revised. and add. - M .: Stroyizdat, 1986.- 464 p., Ill. - /one/. The disadvantages of the known analogue include the poorly studied technological capabilities of the preparation of lime, suitable for the manufacture of building materials.

The objective of the invention is to improve the manufacturability and environmental safety of the method of lime production, the ability to control the processes of preparation of the source and final products to produce lime, the degree of decarbonization of which does not exceed 95-97%.

The solution to this problem is achieved by the fact that the method of producing lime is that lime is mined open-pit from a quarry, the composition of quarry limestone is selected, crushed, sorted into fractions, solid fuel is selected, the weight dosage of limestone and solid fuel is calcined in a rotating furnace, the obtained lump lime is discharged, according to the invention, the composition of quarry limestone is selected with a content, wt.%: CaCO _{3 of} at least 91-92, MgCO ₃ - 5, S - 0.058-0.06, P in a minimum amount - up to 0.1 , Al ₂ O ₃ + Fe ₂ O ₃ - 2.5-2.8, limestone is sorted into fractions of 3-11, 12-24 and 25-40 mm, limestone moisture is estimated at 15-25%, solid fuel is shipped from the warehouse, through coaxially located openings according to the axis of rotation of the rotary drum of the mill feeds dust particles of crushed material into the dust collector, at a weight dosage of limestone and solid fuel, fuel fractions of less than 20 mm are sifted out, a weight dosage of the charge is made with simultaneous magnetic control for the presence of metal inclusions that are removed from ihty, the charge charged in the furnace where the batch mixing is carried out with carbon dioxide CO _2, the charge is fired at 450-1000 ° C for 4-5 minutes to obtain a lump lime fraction 8-30 mm, comprising, in weight.%: most active substances CaO + MgO - 86-88, СО ₂ -3-5.

Method description

The method of producing lime is characterized in that:

- choose the composition of quarry limestone with a content, wt.%: CaCO ₃ not less than 91-92, MgCO ₃ - 5, S - 0.058-0.06, P in a minimum amount - up to 0.1, Al ₂ O ₃ + Fe ₂ O ₃ - 2.5-2.8;

- crushed limestone of a fraction of 120-200 mm in cascade or "waterfall" dropping spherical loads on it - limestone is sorted by control measurements of fractions (from 40-20, 25-12, 11-3 mm);

- sort limestone into fractions of 3-11, 12-24 and 25-40 mm;

- evaluate the moisture content of limestone - 15-25%;

- produce shipment of solid fuel from the warehouse;

- through coaxially located holes along the axis of rotation of the rotary drum of the mill, dust particles of crushed material are fed into the dust collector;

- screen out fuel fractions less than 20 mm in diameter;

- meter the mass fraction of fuel;

- prepare the weight dosage of the mixture;

- produce a weight dosage of limestone and screening of fuel fractions less than 20 mm in diameter;

- produce a weight dosage of the charge with simultaneous magnetic control for the presence of metal inclusions that are removed from the charge;

- load the mixture into the furnace, where the mixture is mixed with carbon dioxide CO ₂ ;

- burn the mixture at 450-1000 ° C for 4-5 minutes;

- get lump lime fraction 8-30 mm, containing, wt.%: the most active substances CaO + MgO - 86-88, CO ₂ - 3-5;

- produce shipment of lump lime.

An example of the method

The method of producing lime is carried out in such a way that:

1) choose the composition of quarry limestone with a content, wt.%: CaCO ₃ at least 91-92, MgCO ₃ - 5, S - 0.058-0.06, P in a minimum amount - up to 0.1, Al ₂ O ₃ + Fe ₂ O ₃ - 2.5-2.8 and limestone is mined in an open way from a quarry;

2) load the mill with spherical loads;

3) crush limestone of a fraction of 120-200 mm by cascading or "waterfall" dropping of spherical loads on it, sort limestone into fractions of 3-11, 12-24 and 25-40 mm;

5) evaluate the moisture content of limestone (15-25%);

6) choose solid fuel - brown coal, which constitutes at least 15-25% by weight of limestone, based on maintaining the fuel's combustion temperature within 800-850 ° C and obtaining calcined lime during gradual heating of the fractions (3-11, 12-24 and 25 -40 mm), produce fuel shipment from the warehouse;

7) through the coaxially located holes along the axis of rotation of the rotary drum of the mill, dust particles of crushed material are fed into the dust collector;

8) fuel fractions of less than 20 mm in diameter, which is 8-10% of lump coal, are screened out; brown coal is weighed in weight - from 150 to 300 kg per 1 m ³ of furnace volume and limestone - 1000-1250 kg per 1 m ^{3 of} furnace;

9) prepare a weight dosage of the charge, the total volume of which is divided into 3 portions with simultaneous magnetic control for the presence of metal inclusions, which are removed from the charge and load the batch dosed in the weight components into the furnace in portions for 10 minutes with active fuel combustion;

10) burn the mixture in a rotary kiln at a temperature of 450-1000 ° C for 4-5 minutes,

11) get lump lime fraction 8-30 mm, containing, wt.%: The most active substances CaO + MgO - 86-88, CO ₂ - 3-5;

12) produce shipment of lump lime.

The industrial usefulness of the new technical solution is to increase the technological capabilities of the method associated with a number of operations for the production of lime composition, and the selection of soaring and pulverized particles from the grinding drum of the mill increases the environmental protection of the preparation of lime compositions.

The economic feasibility of the process lies in the possibility of controlling the processes of preparing the initial and final products of the technological process for the preparation of lime compositions.

Claims (1)

A method of producing lime, which consists in extracting limestone from an open pit, choosing the composition of quarry limestone, crushing it, sorting it into fractions, choosing solid fuel, weighing the dosage of limestone and solid fuel, calcining the resulting mixture in a rotary kiln, unloading the obtained lump lime , characterized in that the composition of the quarry limestone is selected with a content, wt.%: CaCO _{3 of} at least 91-92, MgCO ₃ - 5, S - 0.058-0.06, P in a minimum amount - up to 0.1, Al ₂ O ₃ + Fe ₂ O ₃ - 2.5-2.8, crushed limestone fractions 120-200 mm helmet by ball or drop falling onto it, limestone is sorted into fractions of 3-11, 12-24 and 25-40 mm, limestone moisture is estimated at 15-25%, solid fuel is shipped from the warehouse through coaxially located openings along the axis of rotation of the rotary drum of the mill, dusty particles of crushed material are fed into the dust collector, at a weight dosage of limestone and solid fuel, fractions of solid fuel are screened out less than 20 mm, a weight dosage of the charge is made with a simultaneous magnetic control role for the presence of metal inclusions that are removed from the charge, load the mixture into the furnace, where the mixture is mixed with carbon dioxide CO ₂ , the mixture is burned at 450-1000 ° C for 4-5 minutes to obtain lump lime fraction 8-30 mm containing , wt.%: the most active substances CaO + MgO - 86-88, CO ₂ - 3-5.