CN101209851A

CN101209851A - Method for manufacturing rice-shaped precipitated calcium carbonate

Info

Publication number: CN101209851A
Application number: CNA2007101728533A
Authority: CN
Inventors: 施晓旦; 王彦华; 顾明
Original assignee: Shanghai Dongsheng New Material Co Ltd
Current assignee: Shanghai Dongsheng New Material Co Ltd
Priority date: 2007-12-24
Filing date: 2007-12-24
Publication date: 2008-07-02

Abstract

The invention provides rice-shaped precipitation calcium carbonate, a preparation method and the application thereof. The preparation method comprises the steps that: (1) crystal control agent is added into calcium hydroxide aqueous suspension to obtain mixture; (2) the mixture of the first step is communicated with carbon dioxide for carbonization reaction until the pH value of the mixture reaches 6.5-8.5 and the rice-shape calcium carbonate is collected from the reaction products; the crystal control agent is soluble carbonate. The rice-shape calcium carbonate of the invention has moderate length diameter ratio, which is easier to be maintained in paper fiber than ordinary light calcium carbonate, and increases the smoothness of the paper at the same time; furthermore, the invention not only preserves the printing quality of the paper, but also reduces the consumption of filler and increases retention rate, meanwhile, the manufactured paper has superior characteristics of high stiffness and high smoothness and has no problems of alkali recycling and discharging, being easy for implementing industrialized production.

Description

A kind of manufacture method of rice-shaped precipitated calcium carbonate

Technical field

The present invention relates to a kind of manufacture method of precipitated chalk.

Background technology

In paper-making process, add mineral filler, lime carbonate for example, purpose is to improve whiteness, opaqueness, smoothness, writing quality and the oil absorbency etc. of paper product, in addition, because the raising of wood pulp cost makes cheap lime carbonate become the first-selection of filler.Because the popularization gradually of neutrality and alkaline paper-making technology, acid nonfast filler-calcium carbonate just is applied widely.

Filler mainly contains water-ground limestone and light calcium carbonate with lime carbonate, and the former is from dried, the wet method mechanical disintegration of natural limestone, and the latter is from chemical reaction.

Yet, by the water-ground limestone that the natural limestone mechanical disintegration goes out, add insert paper product after, the whiteness of paper product, opaqueness, smoothness, writing quality and ink absorption can be satisfactory.Just the problems referred to above can be obviously improved with precipitated chalk,, the bulk of paper can be improved because it has the characteristics of low densityization.Guarantee Gas permeability and smoothness preferably simultaneously.

The main synthetic method of precipitated chalk has now: 1. earlier become unslaked lime by limestone calcination, be digested to milk of lime then, feed the method for carbonic acid gas carbonization at last; 2. by the method for yellow soda ash and calcium chloride reaction; 3. by the method for yellow soda ash and milk of lime reaction; From reduce cost and practical application as can be seen, it is more extensive that method 1 is used.Method 2, method 3, for example the cost according to Chinese patent CN1264752C causticization method production precipitated chalk is too high, has problems such as alkali discharging, processing recovery after reaction is finished.

Summary of the invention

The object of the present invention is to provide a kind of preparation method of grain of rice shape lime carbonate, to overcome the above-mentioned defective that prior art exists.

Method of the present invention comprises the steps:

(1) in the calcium hydroxide aqeous suspension, adds the crystal control agent, obtain mixed solution;

(2) in the described mixed solution of step 1), feed carbon dioxide and carry out carburizing reagent, when carbonization is 6.5-8.5 to pH of mixed, from reaction product, collect described grain of rice shape lime carbonate;

Carbonization temperature is 15-85 ℃;

Described crystal control agent is the soluble carbon hydrochlorate, preferred alkaline earth metal carbonate, especially preferred yellow soda ash or salt of wormwood;

The addition of described crystal control agent is the 1-5% with respect to the calcium hydroxide quality;

The mass concentration of described calcium hydroxide aqeous suspension is 10-30%;

Adopt the grain of rice shape lime carbonate of method preparation of the present invention, all very effective as papermaking filler or papermaking paint.

The method that the present invention utilizes carbonization initial stage generation crystal seed to control crystal growing process obtains grain of rice type lime carbonate, and this kind lime carbonate is because length-to-diameter ratio is moderate, and more common light calcium carbonate is easier to be kept in paper fibre, increases paper smoothness simultaneously; Also short slightly in addition than the long stapled filler of synthetic among the Chinese patent CN1931723A, arrange tightr, be difficult for forming burr in the paper surface perk, reduce performances such as paper smoothness, also be difficult for simultaneously producing the gap with paper fibre, on paper, produce phenomenons such as pin hole, not only kept paper press quality, but also reduced the consumption of filler, increased retention rate, simultaneously also make the paper product of producing possess high-quality characteristics such as high-stiffness, high smoothness, and the problem that does not have alkali to reclaim, discharge is carried out suitability for industrialized production easily.

Description of drawings

Fig. 1 is the stereoscan photograph of embodiment 1.

Fig. 2 is the stereoscan photograph of embodiment 6.

Embodiment

Embodiment 1

In the 2500ml beaker, adding concentration is the lime slurry 1600g of 10wt%, continue to add 1% yellow soda ash 1.6g then, be warming up to 15 ℃ of beginning carbonizations after mixing, stirring velocity 200rpm reacts to pH value of solution to 7.5 after-filtration, obtains filter cake 520g, the dry back equal particle diameter 3.2 μ m of lining (JL-1155 of Jingxin Power Testing Apparatus Co., Ltd., Chengdu type laser particle size distribution tests instrument), crystal shape is grain of rice shape (JSM-5300 of NEC company scanning electron microscope observation) (seeing accompanying drawing 1).

Embodiment 2

In the 2500ml beaker, adding concentration is the lime slurry 1600g of 20wt%, continue to add 3% sodium bicarbonate 9.6g then, be warming up to 50 ℃ of beginning carbonizations after mixing, stirring velocity 200rpm reacts to pH value of solution to 6.5 after-filtration, obtains filter cake 680g, the equal particle diameter 4.8 μ m of dry back lining, crystal shape is a grain of rice shape.

Embodiment 3

In the 2500ml beaker, adding concentration is the lime slurry 1600g of 30wt%, continue to add 5% salt of wormwood 24g then, mix and be warming up to 60 ℃ of beginning carbonizations, stirring velocity 200rpm reacts to pH value of solution to 8.0 after-filtration, obtains filter cake 810g, the equal particle diameter 5.5 μ m of dry back lining, crystal shape is a grain of rice shape.

Embodiment 4

In the 2500ml beaker, adding concentration is the lime slurry 1600g of 10wt%, continue to add 3% yellow soda ash 4.8g then, be warming up to 30 ℃ of beginning carbonizations after mixing, stirring velocity 200rpm reacts to pH value of solution to 7.4 after-filtration, obtains filter cake 395g, the equal particle diameter 3.5 μ m of dry back lining, crystal shape is a grain of rice shape.

Embodiment 5

In the 2500ml beaker, adding concentration is the lime slurry 1600g of 20wt%, continue to add 3% salt of wormwood 9.6g then, be warming up to 60 ℃ of beginning carbonizations after mixing, stirring velocity 200rpm reacts to pH value of solution to 7.4 after-filtration, obtains filter cake 575g, the equal particle diameter 4.1 μ m of dry back lining, crystal shape is a grain of rice shape.

Embodiment 6

In the 2500ml beaker, adding concentration is the lime slurry 1600g of 30wt%, continue to add 2% volatile salt 9.6g then, be warming up to 85 ℃ of beginning carbonizations after mixing, stirring velocity 200rpm reacts to pH value of solution to 7.0 after-filtration, obtains filter cake 850g, the equal particle diameter 5.0 μ m of dry back lining, crystal shape is grain of rice shape (seeing accompanying drawing 2).

Embodiment 7

Application Example

Use the dynamic drainage instrument and investigate the reservation situation of grain of rice shape lime carbonate in paper, with reference to the method for using among the Chinese patent CN1931723.

Sample adds and fills out the application result that obtains behind the pattern for pressing the fibrous light cakium carbonate of Chinese patent CN1931723A preparation in the comparative example 1.

Claims

1. the manufacture method of a rice-shaped precipitated calcium carbonate is characterized in that, comprises the steps:

Described crystal control agent is the soluble carbon hydrochlorate.

2. method according to claim 1 is characterized in that, the crystal control agent is an alkaline earth metal carbonate.

3. method according to claim 1 is characterized in that, the crystal control agent is yellow soda ash or salt of wormwood.

4. method according to claim 1 is characterized in that the addition of described crystal control agent is with respect to the 1-5% of calcium hydroxide quality.

5. method according to claim 1 is characterized in that, the mass concentration of described calcium hydroxide aqeous suspension is 10-30%.

6. method according to claim 1 is characterized in that, carbonization temperature is 15-85 ℃.

7. according to the rice-shaped precipitated calcium carbonate of each described method preparation of claim 1～6.

8. the application of rice-shaped precipitated calcium carbonate according to claim 7 is characterized in that, is used as papermaking filler or papermaking paint.