Method for synthesizing hydroxyapatite from alkali residue

A hydroxyapatite and alkali slag technology, applied in chemical instruments and methods, phosphorus compounds, inorganic chemistry, etc., to achieve the effect of reducing synthesis cost, high product purity, and good reproducibility

Inactive Publication Date: 2013-09-25
NANJING UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

At present, there is no report at home and abroad on the technology of using alkali slag to synthesize hydroxyapatite

Method used

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  • Method for synthesizing hydroxyapatite from alkali residue
  • Method for synthesizing hydroxyapatite from alkali residue
  • Method for synthesizing hydroxyapatite from alkali residue

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] Weigh 50 g of alkali slag powder that has been dried and ground to 140 mesh, add it to 1 mol / L hydrochloric acid at a solid-to-liquid ratio of 1 g:10 mL, stir the reaction fully, and filter to obtain the filtrate. The pH of the filtrate was adjusted to 9.5 with aqueous ammonia, and the precipitate was removed by filtration. The concentration of Ca ions in the supernatant (calcium source) was quantified by inductively coupled plasma atomic emission spectrometry, and the result was 20 g / L. Prepare 0.3mol / L diammonium hydrogen phosphate solution. Take 100mL of calcium source and slowly add it into 100mL of 0.3mol / L diammonium hydrogen phosphate solution, fully stir and react for 2 hours, then age for 12 hours. The white solid was separated by filtration, washed with water and ethanol, and then dried to obtain a white powder, which was hydroxyapatite.

Embodiment 2

[0033] Take 0.1 g of the hydroxyapatite prepared in Example 1 and add it to 100 mL of wastewater with a lead concentration of 50 mg / L. The change of its removal rate with time is shown in figure 2 , it can be seen from the figure that the removal rate of lead is fast, and the removal rate of 90% can be reached in 30 minutes, and the balance can be reached after 1 hour, and the equilibrium removal rate is 94.2%.

Embodiment 3

[0035] Weigh 70g of alkali slag powder that has been dried and ground to 80 mesh, add it to 1.5mol / L hydrochloric acid at a solid-to-liquid ratio of 1 g:20 mL, stir the reaction fully, and filter to obtain the filtrate. The pH of the filtrate was adjusted to 10.5 with aqueous ammonia, and the precipitate was removed by filtration. The concentration of Ca ions in the supernatant (calcium source) was quantified by inductively coupled plasma atomic emission spectrometry, and the result was 25.5 g / L. Prepare 0.38mol / L sodium dihydrogen phosphate solution. Take 100mL of calcium source and slowly add it into 100mL of 0.38mol / L sodium dihydrogen phosphate solution, fully stir and react for 1 hour, then age for 24 hours. The white solid was separated by filtration, washed with water and methanol for several times, and then dried to obtain a white powder, namely hydroxyapatite.

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Abstract

The invention discloses a method for synthesizing hydroxyapatite from alkali residue. The process of the method comprises the following steps of: (1) drying the alkali residue at 100-105 DEG C, grinding the alkali residue until the alkali residue can pass through a sieve with 80-140 meshes, so as to obtain alkali residue powder for the future use; (2) mixing the alkali residue powder with diluted hydrochloric acid in a solid-liquid ratio (g: mL) of 1: 10 to 1: 20, adequately stirring and then filtering, adjusting the pH of the filtrate to 9.5-10.5, and then removing a precipitate to obtain a supernatant, namely a calcium source; (3) slowly adding the calcium source in phosphate solution until a calcium-phosphorus molar ratio is 1.67, stirring to react for 1-2 hours, and then ageing for 12-24 hours; and (4) filtering and separating the reaction solution to obtain a white precipitate, washing the white precipitate with water and alcohol and drying the white precipitate to obtain white powder, namely hydroxyapatite. According to the method disclosed by the invention, the waste residue-alkali residue of an alkali factory is used as the calcium source, and hydroxyapatite is synthesized by a simple precipitation preparation method, thus reducing the production cost of hydroxyapatite and realizing the environmental protection conception of turning waste into wealth.

Description

technical field [0001] The invention relates to a method for preparing hydroxyapatite, in particular to a method for synthesizing hydroxyapatite by using alkali slag through a precipitation method. Background technique [0002] In recent years, due to its high adsorption capacity, low water solubility and high stability, hydroxyapatite has been gradually used by researchers in environmental pollution control, especially in the treatment of water pollutants such as heavy metals and benzene pollutants. Therefore, the cost of raw materials for hydroxyapatite synthesis is more concerned. Predecessors' patents "such as publication numbers CN1903706, CN101205058, CN101254909, etc." and research papers "such as Zhu Tingting, Yu Zhen, Wu Liuming, nano-hydroxyapatite on Cu 2+ Adsorption of nitrobenzene from aqueous solution by adsorption on nanocrystalline hydroxyapatite; Desalination , 2010, 263, 89-96. "Commercialized Ca(NO 3 ) 2 Waiting for calcium sources to prepare hydroxyap...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B25/32
Inventor 王连军严玉波孙秀云韩卫清李健生沈锦优刘晓东马芳变陈灿黄诚
Owner NANJING UNIV OF SCI & TECH
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