Method for preparing general-purpose cement through chlorination roasting of aluminosilicate

Abstract

15 Abstract A method for preparing a general-purpose cement by chlorination roasting of aluminosilicates is provided, in which a mixture of aluminosilicates and sodium chloride is roasted in a steam atmosphere to obtain a roasted slag. The roasted slag is mixed with a material containing calcium oxide and magnesium oxide and ground to prepare a raw meal powder. The raw meal powder is subjected to oxidative calcination at a temperature not lower than 1240°C, followed by rapid cooling to obtain a calcined slag. The calcined slag is mixed with 0-3% by weight of caustic alkali and ground to obtain the general-purpose cement. Abstract A method for preparing a general-purpose cement by chlorination roasting of aluminosilicates is provided, in which a mixture of aluminosilicates and sodium chloride is roasted in a steam atmosphere to obtain a roasted slag. The roasted slag is mixed with a material containing calcium oxide and magnesium oxide and ground to prepare a raw meal powder. The raw meal powder is subjected to oxidative calcination at a temperature not lower than 1240°C, followed by rapid cooling to obtain a calcined slag. The calcined slag is mixed with 0-3% by weight of caustic alkali and ground to obtain the general-purpose cement. 15 20 25 20 02 94 15 J an 2 02 5 A b s t r a c t A m e t h o d f o r p r e p a r i n g a g e n e r a l - p u r p o s e c e m e n t b y c h l o r i n a t i o n r o a s t i n g o f 2 0 2 5 2 0 0 2 9 4 1 5 J a n 2 0 2 5 a l u m i n o s i l i c a t e s i s p r o v i d e d , i n w h i c h a m i x t u r e o f a l u m i n o s i l i c a t e s a n d s o d i u m c h l o r i d e i s r o a s t e d i n a s t e a m a t m o s p h e r e t o o b t a i n a r o a s t e d s l a g . T h e r o a s t e d s l a g i s m i x e d w i t h a m a t e r i a l c o n t a i n i n g c a l c i u m o x i d e a n d m a g n e s i u m o x i d e a n d g r o u n d t o p r e p a r e a r a w m e a l p o w d e r . T h e r a w m e a l p o w d e r i s s u b j e c t e d t o o x i d a t i v e c a l c i n a t i o n a t a t e m p e r a t u r e n o t l o w e r t h a n 1 2 4 0 ° C , f o l l o w e d b y r a p i d c o o l i n g t o o b t a i n a c a l c i n e d s l a g . T h e c a l c i n e d s l a g i s m i x e d w i t h 0 - 3 % b y w e i g h t o f c a u s t i c a l k a l i a n d g r o u n d t o o b t a i n t h e g e n e r a l - p u r p o s e c e m e n t . 1 5 A b s t r a c t 2 0 2 5 2 0 0 2 9 4 1 5 J a n 2 0 2 5 1 5

Claims

1. A method for preparing a general-purpose cement by chlorination roasting of aluminosilicates, comprising:5      (1) roasting a mixture of the aluminosilicates and sodium chloride in a steamatmosphere followed by fume discharge to obtain a solid roasted slag, wherein main chemical components of the aluminosilicates are SiO2 and Al2O3;(2) quantitatively mixing the solid roasted slag with a material containing CaO and MgO followed by grinding to obtain a powder mixture, or10 grinding the solid roasted slag followed by washing, drying, and mixing with a powder material containing CaO and MgO to obtain a powder mixture;(3) subjecting the powder mixture to oxidative calcination at a temperature not lower than 1240°C until a stable state with liquid phase dominated is formed, and cooling to obtain a calcined slag; and15      (4) mixing the calcined slag with an alkali followed by grinding to obtain thegeneral-purpose cement in a powder form, wherein the alkali is sodium hydroxide, potassium hydroxide or a combination thereof; orgrinding the calcined slag separately to obtain an active powder component of the general-purpose cement for storage, and mixing the active powder component with an 20 aqueous solution of the alkali to produce a slurry of the general-purpose cement for use.

2. The method of claim 1, wherein in step (1), a steam flow rate is at least 60 g^min-hm-2.25      3. The method of claim 1, wherein in step (1), a maximum roasting temperature is800-1000°C.

4. The method of claim 1, wherein in step (1), a holding time at a maximum roasting temperature is at least 1 h.302025200294   15 Jan 20255. The method of claim 1, wherein in a slag produced from the aluminosilicates by oxidative calcination at 950°C, a total weight percentage of SiO2, Al2O3, Fe2O3, CaO, MgO, Na2O and K2O is greater than 90.0%, and a weight ratio of SiO2 to Al2O3 to Fe2O3 to CaO to MgO to a combination of Na2O and K2O is 49.0-82.5: 10.0-46.0: 0-8.1: 05 5.0: 0-9.5: 0-12.2.

6. The method of claim 1, wherein the mixture of the aluminosilicates and sodium chloride in step (1) is produced through steps of:mixing the aluminosilicates with sodium chloride followed by grinding and 10 sieving with an 80-pm square-hole sieve.

7. The method of claim 1, wherein in step (1), the sodium chloride is 45.0% or less of a total weight of SiO2 and Al2O3 in the aluminosilicates.15      8. The method of claim 1, wherein in the calcined slag obtained in step (3), aweight ratio of SiO2 to Al2O3 to Fe2O3 to CaO to MgO to a combination of Na2O and K2O is 30.0-42.0: 10.0-17.0: 0-6.0: 22.0-46.0: 0-16.0: 3.1-8.3.

9. The method of claim 1, wherein in step (4), a mass of the alkali is calculated 20 according to the following formula:(NaOH + 0.713KOH) / the calcined slag = 0-3.0%.

10. The method of claim 1, wherein in step (1), a discharged fume is introduced into water for dissolution and collection, and a resultant aqueous solution is used to 25 produce HCl gas or hydrochloric acid, or for recovering valuable metals.