Control process for controlling calcination of clays for the cement industry

Patent metadata

Field	Value
Publication number	US-2024150247-A1
Application number	US-202218284048-A
Country	US
Kind code	A1
Filing date	Mar 15, 2022
Priority date	Mar 26, 2021
Publication date	May 9, 2024
Grant date	—

Abstract

A control process for controlling a production process for calcined clays with a calciner including, capture of at least one temperature in the calciner, taking of at least one sample of the calcined clay, production of a reproducible size distribution of the sample, adjustment of the sample mass, conditioning of the sample to a first measuring temperature and of an alkali to a first measuring temperature, combining of the sample with an alkali, temporal capture of the energy generated by the sample-alkali mixture, quantitative evaluation of the time-energy profile captured for the first exothermic reaction and determination of the amount of energy released by the sample, correlation of the amount of energy captured with the temperature and residence time captured, and comparison with previously captured combinations, temperature and residence time values.

First claim

1 - 15 . (canceled)

16 . A control process for controlling a production process for calcined clays with a calciner ( 20 ), comprising:
a) capture of at least one temperature in the calciner, b) taking of at least one sample of the calcined clay, c) production of a reproducible size distribution of the sample, d) adjustment of the sample mass to a predefined sample mass, e) conditioning of the sample to a first measuring temperature and of an alkali to a first measuring temperature, f) combining of the sample with an alkali, g) temporal capture of the energy generated by the sample-alkali mixture at constant first measuring temperature for a first period, h) quantitative evaluation of the time-energy profile captured for the first exothermic reaction and determination of the amount of energy released by the sample for the first exothermic reaction, i) correlation of the amount of energy captured with the temperature and residence time captured, and comparison with previously captured combinations of amount of energy, temperature and residence time values, j) active control of the temperature and/or of the residence time in the calciner in the direction of increasing the amount of energy anticipated for a further sample,
where the quantitative evaluation of the time-energy profile captured for the first exothermic reaction takes place for the period from the first minute to minute 120 .

17 . The control process of claim 16 , wherein the production of a reproducible size distribution of the sample takes place by grinding.

18 . The control process of claim 16 , wherein the alkali selected is an alkali metal hydroxide solution having a pH of between 9 and 15.

19 . The control process of claim 18 , wherein the mass of added alkali is 0.5 times to 5 times the mass of the sample.

20 . The control process of claim 16 , wherein the alkali comprises an alkali former and water, where the alkali former and the water in reaction with one another generate a solution having a pH of between 9 and 15.

21 . The control process of claim 20 , wherein the alkali former is selected from the group encompassing alkali metal hydroxide, alkali metal oxide, alkaline earth metal hydroxide, alkaline earth metal oxide, and substances, mixtures or compositions comprising them.

22 . The control process of claim 16 , wherein from production of a reproducible size distribution of the sample to temporal capture of the energy generated by the sample-alkali mixture at constant first measuring temperature for the first period take place automatically in an environment acclimatized to the first measuring temperature.

23 . The control process of claim 16 , wherein the sample mass is adjusted to the mandated sample mass to an accuracy of at least 2%, preferably at least 0.5%, more preferably at least 0.1%, very preferably to at least 0.02%.

24 . The control process of claim 16 , wherein the quantitative evaluation of the time-energy profile captured in step for the first exothermic reaction takes place for the period from the second minute up to minute 70 .

25 . The control process of claim 16 , wherein the first measuring temperature is selected in the range from 20° C. to 40° C.

26 . The control process of claim 16 , wherein the predefined sample mass selected is between 1 g and 200 g, preferably between 2 g and 20 g.

27 . The control process of claim 16 , wherein additionally captures the reactant batches from which and the mixing ratio in which the clay is supplied to the calcination, with the information as to the reactant batches from which and the mixing ratio in which the clay has been supplied to the calcination being used additionally in step i), with control in step j) additionally considering the selection and the mixing ratio between the reactant batches.

28 . The control process of claim 1627 wherein additionally to the characterization of each product batch, the following batch characterization process is carried out, with the following steps:
A) heating of a batch sample to a batch temperature of 600° C. to 1000° C., preferably 600° C. to 950° C., for a batch time of 1 s to 60 min, preferably of 30 s to 20 min, more preferably of 30 s to 5 min,
B) production of a reproducible size distribution of the batch sample,
C) adjustment of the batch sample mass to a predefined sample mass,
D) conditioning of the batch sample to a first measuring temperature,
E) combination of the batch sample with an alkali,
F) temporal capture of the energy generated by the batch sample-alkali mixture at constant first measuring temperature for a first period,
G) quantitative evaluation of the time-energy profile captured in step F) for the first exothermic reaction, and determination of the amount of energy released by the batch sample for the first exothermic reaction.

29 . The control process of claim 28 , wherein an identical first batch temperature and an identical first batch time are selected for all batch samples.

30 . The control process of claim 28 , wherein the batch characterization process is repeated with a second batch temperature and a second batch time.

Assignees

• thyssenkrupp Polysius GmbH
• Thyssenkrupp Ag

Inventors

• Enders Michael
• Grund Guido

Classifications

• C04B33/32 Primary

  Burning methods · CPC title

• C04B33/04

  Clay; Kaolin · CPC title

• G01N33/24

  Earth materials (G01N33/42 takes precedence) · CPC title

• C04B2/10 Primary

  Preheating, burning calcining or cooling (decarbonation during burning of cement raw materials C04B7/43; {obtaining CaO or MgO otherwise than by thermal decomposition of the corresponding carbonates C01F11/02, C01F5/02}) · CPC title

• Y02P40/10

  Production of cement, e.g. improving or optimising the production methods; Cement grinding · CPC title