CN1724379A

CN1724379A - Process for producing toothpaste grade light-weight calcium carbonate

Info

Publication number: CN1724379A
Application number: CN 200510050081
Authority: CN
Inventors: 周新民; 方笑霞; 徐荣殊; 方轶民; 叶平
Original assignee: JIANDE TIANSHI CALCIUM CARBONATE CO Ltd
Current assignee: ZHEJIANG TIANSHI NANO-TECH Co.,Ltd.
Priority date: 2005-06-13
Filing date: 2005-06-13
Publication date: 2006-01-25
Anticipated expiration: 2025-06-13
Also published as: CN100360418C

Abstract

A process for preparing toe toothpaste-class light calcium carbonate includes such steps as hydrating reaction between warm water and lime CaO to obtain Ca(OH)2 slurry, sieving at least two times, cyclone separating to make its Baume gravity be 10-14, pumping it into carbonizing tower, filling mixture of CO2 and N2, reacting, adding crystal form regulator and de-sulfurizer at 50 deg. C, filling kiln gas, terminating reaction, adding de-sulfurizer, metal ion chelating agent, disinfectant and pH regulator, centrifugal dewatering and drying.

Description

The production method of toothpaste grade light-weight calcium carbonate

Technical field

The present invention relates to a kind of chemical synthesis process, especially a kind of is the production method of the toothpaste grade light-weight calcium carbonate of raw material with calcium hydroxide.

Background technology

Light calcium carbonate is a kind of inorganic chemical product with extensive use, traditional and common toothpaste is all using as raw material with water-ground limestone, and clinic study shows, the toothpaste that water-ground limestone is produced is very big to the glaze surface wear of tooth, and harmful substance contents such as heavy metal are very high, do not play good dental care benefits.In recent years, the higher producer (as U.S. Colgare company etc.) of popularity with water-ground limestone gradate for light calcium carbonate be raw material.Traditional Production of Light Calcium Carbonate counterweight metal index is difficult to control, and objectionable impuritiess such as impurity and heavy metal are more.

Summary of the invention

Purpose of the present invention will solve above-mentioned described deficiency exactly, and a kind of production method of toothpaste grade light-weight calcium carbonate is provided.Chemical property good stability, the purity height of the light calcium carbonate of producing, objectionable constituent such as impurity and heavy metal are few, and complete crystalline structure (being spindle shape or spherical) is arranged, even particle size distribution, the light calcium carbonate of suitable toothpaste production usefulness.

The present invention solves the technical scheme that its technical problem adopts.1), 10 ℃ of-50 ℃ of warm water crossing with filter process 5-10 by volume the production method of this toothpaste grade light-weight calcium carbonate mainly may further comprise the steps:: 1 generates Ca (OH) with lime CaO after hydration reaction ₂Slurries, 1000 ~ 1100 ℃ of limestone calcination temperature; 2), Ca (OH) ₂Slurries to the big screen cloth of the above different meshes of secondary at least that passes through, are removed Ca (OH) according to little ₂Impurity in the slurries obtains epigranular, the highly purified slurry of giving birth to, and by wet cyclone, further removes impurity, comprises nonmetal silicon, heavy metals such as lead, and the degree Beaume of giving birth to slurry reaches 10-14Be °; 3), Ca (OH) ₂Slurries are squeezed into carbonating tower by volume pump, feed CO from the carbonating tower bottom ₂, N ₂Gas mixture reacts, and when treating that solution temperature rises to 50 ℃, adds crystal control agent and desulfuration agent, feeds CO in solution ₂Concentration is the kiln gas of 14-20%, and pressure is 0.07-0.09Mpa, is 7 until pH value, reaction adds the desulfuration agent after finishing successively, metal ion chelation agent, sterilizing agent, pH value conditioning agent 4 hours afterwards, centrifuge dehydration is carried out in the product filtration,, obtained lime carbonate at 100 ~ 120 ℃ of temperature dryings; This is reflected at liquid phase and carries out, and adopts the continous way process, and its concrete operations condition is carbonization pressure: 0.07 ~ 0.09Mpa, CO in the kiln gas ₂Concentration is 14 ~ 20%, 50 ~ 60 ℃ of carbonization temperatures.

Described crystal control agent is brown sugar or glucose, described desulfuration agent, and metal ion chelation agent, sterilizing agent, pH value conditioning agent are respectively hydrogen peroxide, Sodium hexametaphosphate 99, chlorinated lime and phosphoric acid.Described crystal control agent, desulfuration agent, the volume percent of the add-on of metal ion chelation agent, sterilizing agent and pH value conditioning agent is: brown sugar is 0.01 ~ 0.02%, hydrogen peroxide is 0.1 ~ 0.2%, Sodium hexametaphosphate 99 is 0.005 ~ 0.01%, chlorinated lime is 0.002 ~ 0.01%, phosphoric acid is 0.01 ~ 0.02%, and glucose is 0.01 ~ 0.1%.

Effect of the present invention is: replace common coal pit with the combustion gas shaft kiln, replaced traditional coal fuel sintering technology with liquefied gas, use this technology, heavy metal in the coal and other detrimental impurity can not brought in the product, and reasonably control calcining temperature 1000-1100C, automatically control the into slurry time by the reagent that adds, crystal shape complete (being spindle shape or spherical), the crystallographic dimension of guaranteeing to generate lime carbonate are even.By the output capacity of method finished product of the present invention higher (be traditional fine particle calcium carbonate 1.1 times), the product whiteness height, objectionable impuritiess such as heavy metal are atomic, and its quality index reaches the top standard of external product.Use liquefied gas to be fuel, selectivity is good, and by product is few, and the output of waste gas is atomic or do not have the three wastes that produce in this products production, treated allow compliance with emission standards.

Embodiment

Below in conjunction with embodiment the present invention is further described.

Embodiment 1: the production method of this toothpaste grade light-weight calcium carbonate mainly may further comprise the steps:

1), 40 ℃ of warm water 7: 1 by volume and the lime CaO that crosses with filter process generates Ca (OH) after hydration reaction ₂Slurries, 1000 ~ 1100 ℃ of limestone calcination temperature; Wherein Wingdale employing high purity, heavy metal and the atomic fine and close Wingdale of impurity thereof are raw material, and specific targets are as follows: purity 〉=99.5%, iron level≤80ppm, heavy metal≤20ppm, lead content≤2ppm, arsenic content≤2ppm, Mg content≤0.3%.

2), Ca (OH) ₂Slurries are respectively 125 orders, 200 orders and 320 orders according to the little screen cloth that arrives big time by three different meshes, remove Ca (OH) ₂Impurity in the slurries obtains epigranular, the highly purified slurry of giving birth to, and by wet cyclone, further removes impurity, comprises nonmetal silicon, and heavy metals such as lead, degree Beaume reach 11.5Be ° of Ca (OH) ₂1500 milliliters of solution;

3), Ca (OH) ₂Slurries are squeezed into carbonating tower by volume pump, from carbonating tower bottom with going into CO ₂, N ₂Gas mixture reacts, and when treating that solution temperature rises to 50 ℃, adds crystal control agent brown sugar 0.35% (volume percent) and desulfuration agent hydrogen peroxide 0.3% (volume percent), feeds CO in solution ₂Concentration is the kiln gas of 14-20%, pressure is 0.07-0.09Mpa, until pH value is 7, after reaction finishes, adding volume percent successively is desulfuration agent hydrogen peroxide 0.07%, after the metal ion chelation agent Sodium hexametaphosphate 99 0.004%, sterilizing agent chlorinated lime 0.09%, pH value conditioning agent phosphoric acid 0.3% 4 hours, product is filtered carry out centrifuge dehydration, at 120 ℃ of temperature dryings, obtain 258g lime carbonate; Use the sem observation crystal formation, median size is the spindle-type light calcium carbonate of 5.5 μ m, meets the toothpaste production requirement.

This is reflected at liquid phase and carries out, and adopts the continous way process, and its concrete operations condition is carbonization pressure: 0.07 ~ 0.09Mpa, CO in the kiln gas ₂Concentration is 14 ~ 20%, 50 ~ 60 ℃ of carbonization temperatures.After the dehydration workshop section in step 3), form strict microorganism supervisory system, prevent the pollution of artificial or implements etc. by sterilization equipments such as sterilization, ultraviolet ray, infrared lights, total plate count is controlled at≤100fu/g in the microbiological indicator the most at last, and mould, yeast, the blue formula negative bacillus of leather must not be found in detection.

Embodiment 2:

Crystal control agent brown sugar among the embodiment 1 is replaced with glucose, and other conditions are all identical with example 1, obtain lime carbonate 255g, and the crystal median size is the spindle-type light calcium carbonate of 5.2 μ m, meets the toothpaste production requirement.

Embodiment 3:

Be with the difference of embodiment 1: the warm water with the CaO that generates in the kiln and 35 ℃ is made into the Ca that degree Beaume is 11.5Be (OH) ₂8 tons of solution, treat to add when solution temperature is 50 ℃ brown sugar 0.35% (volume percent, down together), hydrogen peroxide 0.3% is sent in the carbonating tower again, and feeding gas concentration lwevel at the bottom of tower is the kiln gas of 14-20%, pressure is 0.07-0.09Mpa, until pH value is 7, and temperature is about 60 ℃, lasts 1 hour, after reaction finishes, add hydrogen peroxide 0.07% successively, Sodium hexametaphosphate 99 0.004%, chlorinated lime 0.09%, phosphoric acid 0.3% 4 hours afterwards, centrifuge dehydration then at 120 ℃ of temperature dryings, obtains toothpaste grade light-weight calcium carbonate.Use the sem observation crystalline form, median size is the spindle-type light calcium carbonate of 5.5 μ m, and following the tracks of check point in process of production has: ore, water, CaO, CO ₂, Ca (OH) ₂13 of slurries, carbonization slurries, pulp storage tank (giving birth to slurry, ripe slurry), dehydration powder, oven dry powder, work in-process, finished products etc.After the dehydration workshop section, form strict microorganism supervisory system, prevent the pollution of artificial or implements etc. by sterilization equipments such as sterilization, ultraviolet ray, infrared rays, total plate count in the microbiological indicator is controlled at≤100fu/g the most at last, and mould, yeast, the blue formula negative bacillus of leather must not be found in detection.

The contrast of table 1 lime carbonate physical and chemical index

Sequence number	Project	Index	Example one	Example two	Example three
Sequence number	Project	Index	Example one	Example two	Example three	1	Lime carbonate is (with CaCO ₃Meter) (in butt), % 〉=	98.5	98.7	98.6	98.6
2	Volatile content below 105 ℃, %≤	0.5	0.2	0.2	0.1	1	Lime carbonate is (with CaCO ₃Meter) (in butt), % 〉=	98.5	98.7	98.6	98.6
2	Volatile content below 105 ℃, %≤	0.5	0.2	0.2	0.1	3	PH value (20% turbid liquid)	8.5-9.5	9.3	9.4	9.0
4	Hydrochloric acid acid non-soluble substance content, %	0.2	0.1	0.1	0.1	3	PH value (20% turbid liquid)	8.5-9.5	9.3	9.4	9.0
4	Hydrochloric acid acid non-soluble substance content, %	0.2	0.1	0.1	0.1	5	Free alkali content (in Na2O), %	0.07	0.07	0.07	0.07
6	Fe content, %	0.01	0.01	0.01	0.01	5	Free alkali content (in Na2O), %	0.07	0.07	0.07	0.07
6	Fe content, %	0.01	0.01	0.01	0.01	7	Magnesium (Mg) content, %	0.3	0.15	0.2	0.1
8	Whiteness, degree	94	94.5	94.7	95	7	Magnesium (Mg) content, %	0.3	0.15	0.2	0.1
8	Whiteness, degree	94	94.5	94.7	95	9	Settling volume, ml/g	1.7-2.1	1.9	2.0	1.8
10	Sieve thing (crossing the 45um testing sieve), %	99.9	100.0	100.0	100.0	9	Settling volume, ml/g	1.7-2.1	1.9	2.0	1.8
10	Sieve thing (crossing the 45um testing sieve), %	99.9	100.0	100.0	100.0	11	Heavy metal (in Pb) content, %	0.002	＜0.002	＜0.002	＜0.002
12	Barium (Ba) content	By	By	By	By	11	Heavy metal (in Pb) content, %	0.002	＜0.002	＜0.002	＜0.002
12	Barium (Ba) content	By	By	By	By	13	Chloride content, %	0.005	＜0.005	＜0.005	＜0.005
14	Apparent density, g/ml	0.64-0.75	0.7	0.72	0.68	13	Chloride content, %	0.005	＜0.005	＜0.005	＜0.005
14	Apparent density, g/ml	0.64-0.75	0.7	0.72	0.68	15	Sulfide	Must not detect	Do not detect	Do not detect	Do not detect

The contrast of table 2 lime carbonate sanitary index

Sequence number	Project	Index	Example one	Example two	Example three
Sequence number	Project	Index	Example one	Example two	Example three	1	Plumbous (Pb) content, %≤	0.0002	0.0001	0.0001	0.0001
2	Arsenic (As) content, %≤	0.0002	＜0.0001	＜0.0001	＜0.0001	1	Plumbous (Pb) content, %≤	0.0002	0.0001	0.0001	0.0001
2	Arsenic (As) content, %≤	0.0002	＜0.0001	＜0.0001	＜0.0001	3	Total plate count, cfu/g≤	100	50	65	＜10
4	Mould and yeast, cfu/g≤	100	60	70	＜10	3	Total plate count, cfu/g≤	100	50	65	＜10
4	Mould and yeast, cfu/g≤	100	60	70	＜10	5	Streptococcus aureus	Must not detect	Do not detect	Do not detect	Do not detect
6	Remove from office blue formula negative bacillus	Must not detect	Do not detect	Do not detect	Do not detect	5	Streptococcus aureus	Must not detect	Do not detect	Do not detect	Do not detect

Claims

1, a kind of production method of toothpaste grade light-weight calcium carbonate is characterized in that: mainly may further comprise the steps:

1), 10 ℃ of-50 ℃ of warm water crossing with filter process 5-10 by volume: 1 generates Ca (OH) with Wingdale CaO after hydration reaction ₂Slurries, 1000 ~ 1100 ℃ of limestone calcination temperature;

2), Ca (OH) ₂Slurries to the big screen cloth of the above different meshes of secondary at least that passes through, are removed Ca (OH) according to little ₂Impurity in the slurries obtains epigranular, the highly purified slurry of giving birth to, and by wet cyclone, further removes impurity, and the degree Beaume of giving birth to slurry reaches 10-14Be °;

3), Ca (OH) ₂Slurries are squeezed into carbonating tower by volume pump, feed CO from the carbonating tower bottom ₂, N ₂Gas mixture reacts, and when treating that solution temperature rises to 50 ℃, adds crystal control agent and desulfuration agent, feeds CO in solution ₂Concentration is the kiln gas of 14-20%, and pressure is 0.07-0.09Mpa, is 7 until pH value, reaction adds the desulfuration agent after finishing successively, metal ion chelation agent, sterilizing agent, pH value conditioning agent 4 hours afterwards, centrifuge dehydration is carried out in the product filtration,, obtained lime carbonate at 100 ~ 120 ℃ of temperature dryings; This is reflected at liquid phase and carries out, and adopts the continous way process, and its concrete operations condition is carbonization pressure: 0.07 ~ 0.09Mpa, CO in the kiln gas ₂Concentration is 14 ~ 20%, 50 ~ 60 ℃ of carbonization temperatures.

2, the production method of toothpaste grade light-weight calcium carbonate according to claim 1, it is characterized in that: it is raw material that described Wingdale adopts high purity, heavy metal and the atomic fine and close Wingdale of impurity thereof, specific targets are as follows: purity 〉=99.5%, iron level≤80ppm, heavy metal≤20ppm, lead content≤2ppm, arsenic content≤2ppm, Mg content≤0.3%.

3, the production method of toothpaste grade light-weight calcium carbonate according to claim 1 is characterized in that: in step 2) described in Ca (OH) ₂Slurries to big the screen cloth by three different meshes, are respectively 125 orders, 200 orders and 320 orders according to little.

4, the production method of toothpaste grade light-weight calcium carbonate according to claim 1, it is characterized in that: after the dehydration workshop section in step 3), by sterilization, ultraviolet ray, the disinfection of Infrared sterilization equipment, total plate count is controlled at≤100fu/g in the microbiological indicator the most at last, and mould, yeast, the blue formula negative bacillus of leather must not have discovery in detection.

5, the production method of toothpaste grade light-weight calcium carbonate according to claim 1 is characterized in that: described crystal control agent is brown sugar or glucose.

6, the production method of toothpaste grade light-weight calcium carbonate according to claim 1 is characterized in that: described desulfuration agent, metal ion chelation agent, sterilizing agent, pH value conditioning agent are respectively hydrogen peroxide, Sodium hexametaphosphate 99, chlorinated lime and phosphoric acid.

7, according to the production method of claim 1 or 5 or 6 described toothpaste grade light-weight calcium carbonates, it is characterized in that: described crystal control agent, desulfuration agent, the volume percent of the add-on of metal ion chelation agent, sterilizing agent and pH value conditioning agent is: brown sugar is 0.01 ~ 0.02%, hydrogen peroxide is 0.1 ~ 0.2%, Sodium hexametaphosphate 99 is 0.005 ~ 0.01%, chlorinated lime is 0.002 ~ 0.01%, and phosphoric acid is 0.01 ~ 0.02%, and glucose is 0.01 ~ 0.1%.