CN1291916C

CN1291916C - Process for preparing fluorine reducing ion sieve of aquatic body

Info

Publication number: CN1291916C
Application number: CN 200510013654
Authority: CN
Inventors: 孙岩; 王榕树; 那平; 刘剑锋; 张海燕
Original assignee: Tianjin University
Current assignee: Tianjin University
Priority date: 2005-06-03
Filing date: 2005-06-03
Publication date: 2006-12-27
Anticipated expiration: 2025-06-03
Also published as: CN1724362A

Abstract

The present invention discloses a method for preparing a fluorine-reducing ion sieve of an aquatic body, which belongs to the field of an inorganic fluoride-removing material. The method comprises the following steps: sulfuric acid is dripped to the water solution of sodium silicate under a stirring condition, so that silicic acid gel is prepared when the pH value reaches 7 to 8; next, the silicic acid gel is aged for 10 to 30 hours at the temperature of 25 to 30 DEG C to prepare a porous, continuous and stable skeleton structure; the soluble water solution of zirconium oxychloride or cerous sulfate is dripped to the silicic acid gel under a stirring condition to obtain the bound gel of fluorine removal matters and carriers; the bound gel is filtered to remove free water, and a filter cake is washed; finally, the bound gel is processed by drying, calcination and heat insulation to obtain the fluorine-reducing ion sieve. The method has the advantages that the prepared fluorine-reducing ion sieve has the characteristics of good mechanical strength and uniform particles, and has high adsorption speed and large adsorption capacity for fluorine ions in water. When the fluorine-reducing ion sieve is used for processing raw water with 10 mg/L of fluoride ion content, the average adsorption capacity is greater than 6 gF/Kg under the condition that the fluorine ion content in the outflow water is below 1.0 mg/L.

Description

The preparation method who falls the fluorion sieve of water body

Technical field

The present invention relates to a kind of preparation method who falls the fluorion sieve of water body, belong to inorganic defluorination material field.

Background technology

The fluorinated water defluorination method mainly contains absorption method, electrocoagulation, reverse osmosis method, ion exchange method and coagulant sedimentation etc. at present.Ion exchange method expense height wherein, and to the water quality requirement strictness; Electrocoagulation device complexity, current consumption is big; And that the fluorine content of the water that chemical precipitation method and coagulation sedimentation are handled will reach the index of 1mg/L is big than difficulty and sludge quantity; Because with the reverse osmosis is the rise of the membrane technique of representative, the practice that application reverse osmosis, electrodialytic technique are handled fluorinated water day by day increases, but because the characteristics of reverse osmosis and osmosis self, it does not really shift out the fluorine element in the water from water, and just it is concentrated in that part of water of discharging, this is marrying again of a kind of contradiction, only is the unilateral qualified tap water that provides.And fluorine still is present in the water body, and the fluoride pollution problem of water is not solved completely, is still keeping the people is caused the possibility of injury.If further contemplate the consumption of electric energy and the waste of discharge waste water, its value may be negative value.Especially in the area of China's water of high fluorine content, generally be the relative area that falls behind, area of lack of water with economy, therefore select for use with the desalination be the membrane process of characteristics handle contain fluorine drinking water be unreasonable also be uneconomic.Using more absorption method defluorination is the activated alumina method, and the saturated adsorption capacity of this method when the water body content of fluoride ion is 1mg/L is lower, and exists the aluminum ion of stripping to influence the possibility of HUMAN HEALTH.

Summary of the invention

The object of the present invention is to provide a kind of preparation method who falls fluorion sieve of water body, with this method preparation fall the fluorion sieve have the fluorion rate of adsorption in the water body fast, the characteristics that loading capacity is high.

The present invention is achieved by following technical proposals, with zirconium white, cerium oxide for mainly falling fluorine material, attempt using the method for two-step gelation, once finish the silicon structure carrier and fall combining of fluorine material, temperature-rise period and temperature by the control roasting make it structurally realize ionization, become a kind of better physical strength that has, the evengranular fluorion sieve that falls, its preparation method feature comprises following process:

(1) formation of silicon structure carrier: at the sulfuric acid that in the sodium silicate aqueous solution of 0.05～0.20mol/L, drips 10～25% under 40～60 rev/mins the agitation condition, reach at 7～8 o'clock at pH and form silicic acid gel, in temperature is ageing 10～30 hours under 25～30 ℃ of conditions, in this process, silicic acid forms the spheroidal colloidal particles of poly silicic acid by intermolecular condensation, connect into porous hydrogel by hydrogen bond between micelle, further dehydrating condensation forms the silica dioxide gel particle between hydrogel in weathering process, and be that unit proceeds three-dimensional bonding with the Si-O-Si chain, form porous and successive skeleton structure.

(2) fall combining of fluorine material and carrier: with amount of substance is 5～20% solubility zirconates of step (1) mesosilicic acid sodium amount of substance or the aqueous solution of cerium salt preparation becoming 0.05～0.20mol/L, under 20～50 rev/mins agitation condition, speed with 5～15ml/min drips in step (1) gained gel, the sample that obtains when finishing is white pulpous state system, and wherein homodisperse the silica dioxide gel particle that particle diameter is about 3～5mm.When going into zirconates or cerium salt solution to the silicon gel, absorption and the hydrolysis of silicon gel to it taken place simultaneously, and three-dimensional structure weave at blocky silica gel surface silicon gel and new gel, newly-generated gel is not penetrated into silica gel inside, and two kinds of gels further remove association together by hydroxyl in the drying and dehydrating process.

(3) curing molding: after step (2) gained gel removed free-water after filtration, with deionized water soluble substance in the filter cake is cleaned, again with the gained solid in 90～150 ℃ of oven dry, heat-up rate with 1～5 ℃/min in being placed on stoving oven rises 240～400 ℃ with temperature, and under top temperature, be incubated 1～3h, promptly get and fall fluorion sieve finished product.

The invention has the advantages that: falling fluorion sieve finished product is a kind of better physical strength that has, and evengranular material, this fluorine reducing agent have the fluorion rate of adsorption in the water body fast, the characteristics that loading capacity is high.When being used to handle content of fluoride ion and being the former water of 10mg/L, guaranteeing that the water outlet content of fluoride ion is lower than under the prerequisite of 1.0mg/L, average loading capacity is greater than the 6gF/Kg fluorine reducing agent.

Embodiment

Example 1

At the sulfuric acid that in the sodium silicate aqueous solution of 0.1mol/L, drips 25% under 60 rev/mins the agitation condition, reach at 7～8 o'clock and form the silicon gel at pH, be ageing 12 hours under 25～30 ℃ of conditions in temperature.Treat that the ageing of silicon gel is complete, the speed with 10ml/ minute under 40 rev/mins agitation condition drips the 0.01mol/L zirconium oxychloride aqueous solution in gelling system.The sample that obtains when finishing is white pulpous state system, and wherein homodisperse the gel particle that particle diameter is about 3-5mm, and 4 hours after-filtration of ageing wash to the wash water chloride ion content less than 10mg/L, with solid in 110 ℃ of dryings.Dried product is heated to 240 ℃ with the heat-up rate of 2 ℃/min, is incubated 1 hour, cooling naturally, finished product promptly.When this finished product is used to handle content of fluoride ion and is the former water of 10mg/L, guaranteeing that the water outlet content of fluoride ion is lower than under the prerequisite of 1.0mg/L, average loading capacity is the 6.8gF/Kg fluorine reducing agent.

Example 2

At the sulfuric acid that in the sodium silicate aqueous solution of 0.075mol/L, drips 15% under 55 rev/mins the agitation condition, reach at 7～8 o'clock and form the silicon gel at pH, be ageing 12 hours under 25～30 ℃ of conditions in temperature.Treat that the ageing of silicon gel is complete, the speed with 5ml/ minute under 35 rev/mins agitation condition drips the 0.15mol/L cerous sulfate aqueous solution in gelling system.The sample that obtains when finishing is white pulpous state system, and wherein homodisperse the gel particle that particle diameter is about 3-5mm, and 4 hours after-filtration of ageing wash to the wash water chloride ion content less than 10mg/L, with solid in 110 ℃ of dryings.Dried product is heated to 310 ℃ with the heat-up rate of 1 ℃/min, is incubated 1.5 hours, cooling naturally, finished product promptly.When this finished product is used to handle content of fluoride ion and is the former water of 10mg/L, guaranteeing that the water outlet content of fluoride ion is lower than under the prerequisite of 1.0mg/L, average loading capacity is 6.5gF/Kg.

Claims

1. the preparation method who falls fluorion sieve of a water body is characterized in that comprising following process:

(1) formation of silicon structure carrier: at the sulfuric acid that in the sodium silicate aqueous solution of 0.05～0.20mol/L, drips 10～25% under 40～60 rev/mins the agitation condition, reach at 7～8 o'clock at pH and form silicic acid gel, in temperature is ageing 10～30 hours under 25～30 ℃ of conditions, in this process, silicic acid forms the spheroidal colloidal particles of poly silicic acid by intermolecular condensation, connect into porous hydrogel by hydrogen bond between micelle, further dehydrating condensation forms the silica dioxide gel particle between hydrogel in weathering process, and be that unit proceeds three-dimensional bonding with the Si-O-Si chain, form porous and successive skeleton structure;

(2) fall combining of fluorine material and carrier: with amount of substance is 5～20% solubility zirconium oxychlorides of step (1) mesosilicic acid sodium amount of substance or the aqueous solution of cerous sulfate preparation becoming 0.05～0.20mol/L, under 20～50 rev/mins agitation condition, speed with 5～15ml/min drips in step (1) gained gel, the sample that obtains when finishing is white pulpous state system, wherein homodisperse the gel particle that particle diameter is 3～5mm, then at the three-dimensional structure weave in of blocky silica gel surface silicon gel and new gel;

(3) curing molding: after step (2) gained gel removed free-water after filtration, with deionized water soluble substance in the filter cake is cleaned, again with the gained solid in 90～150 ℃ of oven dry, the heat-up rate that is placed on again in the stoving oven with 1～5 ℃/min rises 240～400 ℃ with temperature, and under top temperature, be incubated 1～3h, promptly get and fall fluorion sieve finished product.