CN100453464C

CN100453464C - Preparing super fine magnesium hydroxide by wet method from brucite

Info

Publication number: CN100453464C
Application number: CNB2006101460402A
Authority: CN
Inventors: 李继彦; 刘志锋; 吴伯麟
Original assignee: Guilin University of Technology
Current assignee: Guilin University of Technology
Priority date: 2006-10-31
Filing date: 2006-10-31
Publication date: 2009-01-21
Anticipated expiration: 2026-10-31
Also published as: CN1944260A

Abstract

The present invention relates to preparation process of superfine magnesium hydroxide powder with natural ore material, and is especially wet process of preparing superfine magnesium hydroxide powder with brucite. The wet process of preparing superfine magnesium hydroxide includes the following steps: 1. calcining brucite powder in 325 mesh fineness at 450 deg.C-700 deg.C for 1-3 hr to obtain magnesia powder; 2. mixing magnesia powder in 100 weight portions, triethanolamine in 1 weight portion and anhydrous alcohol in 200-300 weight portions, and ball milling the mixture for 24 hr; 3. adding water in 100-200 weight portions before further ball milling for 12 hr; and 4. drying the slurry at 120 deg.C and crushing to obtain superfine magnesium hydroxide powder of average particle size of 370-500 nm. The present invention has low cost, simple technological process and small product particle size.

Description

Preparing super fine magnesium hydroxide by wet method from brucite

Technical field

The present invention relates to the natural crystal is the method for feedstock production super fine magnesium hydroxide powder, particularly preparing super fine magnesium hydroxide by wet method from brucite.

Background technology

Along with the widespread use of macromolecular material in industrial, civilian and even every field, fire retardant material has caused the concern of the whole society.Keep annual growth higher more than 35% at developed country's fire retardants such as the U.S., Europe, Japan in recent years.European Union just put into effect in February, 2003 " about scrapping electric/electronic device instruction " (WEEE) and " ROHS " (ROHS), require that before 2006 legislation restriction is leaded, the use of mercury, cadmium, sexavalent chrome and specific bromide fire retardant PBB, six kinds of objectionable impuritiess of PBDE.10 big series products such as large household appliance, small household appliance, Information technology and telecommunication apparatus, electric and electronic tool have been contained in this instruction, and are mostly the exit electronic electric product that China is main in this 10 big class.European Union accounts for 1/4 of China's household electrical appliances export market at present, and after two instructions of European Union are put into practice, the electric equipment products export amount that China is subjected to directly influence will reach 3 trillion yuan, account for 71% of Chinese exports European Union electronic product total value.

In the application of inorganic combustion inhibitor,, respectively have superiority based on aluminium hydroxide and magnesium hydroxide.And the flame retardant of magnesium hydroxide field is the with the fastest developing speed of feedstock production flame retardant of magnesium hydroxide with the brucite.The structure of brucite is similar to magnesium hydroxide, compares low production cost with the bittern synthesis method, but need handle and surface treatment by micronize.At present the mineral reserve of explored in the world brucite reserves maximum are in China Kuandian, proven reserve 1,000 ten thousand t, and this produces magnesium hydroxide from raw material supply for domestic developing water magnesite and has laid good basis.

More little its homodisperse in macromolecular material that helps more of the particle of fire retardant, thus just more little to the macromolecular material Effect on Performance.At present breaking method roughly is divided into two kinds of dry type and wet types.CN1095080A (application number is 93111803.4) is the method that adopts heat, comminution by gas stream, forms static separation more.Though good product quality but investment is big, energy consumption is big.Dry method does not need drying, is applicable to that median size at the above product of 5 μ m, is difficult to produce the more product of small particle size.The wet pulverization aspect, the CN1356361A (application number 01142497.4) of (day) Ajincomoto Co., Inc application has wherein narrated and adds polyocarboxy acid type dispersion agent and fatty acid metal salt and make the method that median size is the following super fine magnesium hydroxide powder of 10 μ m in brucite or sintered magnesia; The CN1557711A (application number 200410005164.X) of Xinyang Mining Chemical Inst., Zhongshan District, Dalian City's application has wherein narrated and has used vibration mill to prepare the method for the following super fine magnesium hydroxide powder of median size 5 μ m; People such as the Zheng Shuilin of China Mining University use and stir mill, and rotor speed is 1350r/min, and Ф＜0.8～1.8mm zirconia ball is made grinding medium, and trolamine is a grinding aid, has prepared d ₅₀=0.78 μ m, d ₉₇The super fine magnesium hydroxide powder of=2.29 μ m.The magnesium oxide that relates in two parts of patents of CN1557711A of the CN1356361A of (day) Ajincomoto Co., Inc application and Xinyang Mining Chemical Inst., Zhongshan District, Dalian City's application all is the light calcined magnesia that adopts more than 800 ℃ in addition.

Above-described the whole bag of tricks, though can prepare the super fine magnesium hydroxide of certain fineness, but mainly be by the high vibration mill of energy consumption or adopt expensive zirconium oxide microballoons to realize the refinement of granularity, like this at the cost that has increased powder preparing in varying degrees as grinding medium.

Summary of the invention

The objective of the invention is to propose the method for the super fine magnesium hydroxide that a kind of cost is low, technological process simple, easy utilized brucite prepared sizes of producing are thinner.

Concrete steps of the present invention are:

(1) earlier brucite powder was obtained magnesia powder in 1～3 hour 450 ℃～700 ℃ calcinings; The fineness of brucite powder is 325 orders.

(2) in the magnesium oxide of 100 weight parts, add the trolamine of 1 weight part, the dehydrated alcohol of 200～300 weight parts is used general milling machine ball milling 24 hours;

(3) water that adds 100～200 weight parts continued ball milling 12 hours;

(4) slurry is at 120 ℃ of convection dryings, pulverize median size between the magnesium hydroxide ultrafine powder of 370～500 nanometers.

Embodiment

(1) earlier brucite powder was obtained magnesia powder in 3 hours 450 ℃ of calcinings; The fineness of brucite powder is 325 orders.

(2) in the magnesium oxide of 100 weight parts, add the trolamine of 1 weight part, the dehydrated alcohol of 200 weight parts is used general milling machine ball milling 24 hours;

(3) water that adds 100 weight parts continued ball milling 12 hours;

(4) slurry is at 120 ℃ of convection dryings, pulverize the magnesium hydroxide ultrafine powder of median size about 400 nanometers.

Claims

1. method for preparing super fine magnesium hydroxide is characterized in that concrete steps are:

(1) earlier brucite powder was obtained magnesia powder in 1～3 hour 450 ℃～700 ℃ calcinings;

(2) in the magnesia powder of 100 weight parts, add the trolamine of 1 weight part, the dehydrated alcohol ball milling of 200～300 weight parts 24 hours;

(3) water that adds 100～200 weight parts continued ball milling 12 hours;

2. according to the described method for preparing super fine magnesium hydroxide of claim 1, the fineness that it is characterized in that described brucite powder is 325 orders.