CN103641158B - One solid-phase synthesis prepares Ca 2pbO 4the method of powder - Google Patents

Abstract

The invention belongs to Preparation Technique of Powders field, relate to a kind of Ca ₂pbO ₄the preparation method of powder: comprise the following steps: 1) calcium salt is mixed by a certain percentage with lead salt, powder is fully ground to and mixes, 2) compacting in corundum crucible is placed on, and be placed on pyroreaction in retort furnace, 3) grind, sieve, fully wash purifying with washings, filter to isolate product, then obtain high-purity C a with after deionized water wash, filtration, drying ₂pbO ₄powder, the method synthesis material is easy to get, cheaply, technique is simple, easy to operate, the Ca of preparation ₂pbO ₄crystal morphology is homogeneous, and outward appearance is cubic, and crystal formation is complete, and purity can up to more than 99%.

Description

One solid-phase synthesis prepares Ca 2pbO 4the method of powder

Technical field

The invention belongs to field of powder material, relate to a kind of Ca ₂pbO ₄raw powder's production technology.

Background technology

Be new and high technology 21st century with strategic importance according to superconducting material technology, bismuth series superconducting material creates profound influence as the science and technology of superconducting material to contemporary society uniquely obtaining mass-producing application at present.Ca ₂pbO ₄be present in a kind of important component in bismuth series superconducting material, it is formed at the bismuth system superconducting precursor powder heat treatment process initial stage, be considered to indispensable phase composition in bismuth series superconducting material, play an important role in the one-tenth phase process of superconducting material (Yang little Peng etc. amorphous phase TEM research [J] in the BSCCO band at thermal treatment initial stage. Rare Metals Materials and engineering .2013,37 (4): 142-145).Therefore, highly purified Ca is prepared ₂pbO ₄for its concrete effect in bismuth series superconducting material preparation process of research and significant on the impact of bismuth series superconducting material performance.

At present, the chemical process preparing powder is a lot, comprising: gas phase synthesis method, liquid phase reaction method, solid-phase synthesis etc.Gas phase synthesis method mainly comprises gas-phase decomposition method and gas phase synthesis method, is mainly applicable to prepare metal, nitride, carbide, boride etc.Liquid phase reaction method has the precipitator method, sol-gel method, microemulsion method and hydrothermal method etc.When using the precipitator method, prepared material need be obtained by the various chemical reactions in solution, and is precipitated as jelly, washing, filtration difficulty and precipitation agent is easily mixed into product not easily removes.Sol-gel method needs with an organic solvent, easily from solvent, introduces carbon impurity, difficult removal, and crystal easy-sintering.Microemulsion method in two parts of identical microemulsions, adds two kinds of reactants respectively make it chemical reaction occurs, and then isolate product.Hydrothermal method is that powder is generated by nucleating growth by reactant and water heating under high pressure.In above method, what have needs specific equipment, and some technique is more complicated, and raw materials cost is high, and environment protecting is poor, not easily promotes.

It is legal etc. that solid synthesis route comprises thermal decomposition method, composite oxides solid reaction process, reducing, and solid state powder synthesis method preparation technology is simple, without the need to solvent, capacity usage ratio is high, cost is low, productive rate is high, is applicable to scale production.

Summary of the invention

Present invention achieves with solid state powder synthesis method synthesis Ca ₂pbO ₄, the Ca after purified ₂pbO ₄crystalline phase is complete, and crystal morphology is single, and be the cubic structure of rule, purity is higher than 99%.Present method does not introduce any impurity metallic elements in building-up process, and purification process is simple and less demanding to plant and instrument, and in purge process, Pb Elements Leaching is few, environmentally friendly, is applicable to batch production.

Reaction raw materials of the present invention is mixed by calcic and leaded powder, controls the stoichiometric ratio of calcium lead element between 2:1 ~ 3:1.Detailed technology scheme of the present invention is:

One solid-phase synthesis prepares Ca ₂pbO ₄the method of powder, comprises the following steps:

(1) calcium salt and lead salt pressed powder, is taken, fully grind in agate mortar, two kinds of materials are mixed completely, wherein, described calcium salt is calcium oxide or nitrocalcite, described lead salt is lead nitrate or plumbous oxide, and calcium and lead element stoichiometric ratio are between 2:1 ~ 3:1;

(2) mixed powder, by step 1 obtained is placed in compacting in corundum crucible, then crucible is placed in high-temperature roasting in retort furnace, and reaction generates Ca ₂pbO ₄, wherein, temperature controls at 600 ~ 800 DEG C, time 24h;

(3) Ca, step 2 obtained ₂pbO ₄grinding, sieve, with washings ultrasonic cleaning 3 ~ 8 times, each 2 ~ 10min also filters to isolate product, then uses deionized water wash 3 ~ 8 times, and filtration under diminished pressure carries out solid-liquid separation, and drying obtains high-purity C a ₂pbO ₄powder, wherein, is ground to Ca ₂pbO ₄granularity is 60 ~ 120 microns, and described washings is the one in 0.5% ~ 3% ammonium chloride solution, pH=4 ~ 5 hydrochloric acid soln, pH=4 ~ 5 sulphuric acid soln, pH=4 ~ 5 acetum.

The invention has the advantages that: invented Ca ₂pbO ₄solid state powder synthesis method and purification process, present method, in building-up process, does not relate to organic solvent, also without the need to adding other element except Ca, Pb two kinds of elements, therefore can not introduce impurity element.Purification step is simple, washing effect well and do not destroy product structure, use washings easily to remove, noresidue.Ca prepared by the method ₂pbO ₄crystal morphology is homogeneous and regular, and purified rear purity is high.Dried product stable chemical nature, convenient preservation is so that follow-up study.

Present invention process is simple, and reagent raw material is easy to get, and achieves low cost, the high-purity C a of high benefit ₂pbO ₄the preparation method of powdered material, has the economic feasibility of industrialized production.Products obtained therefrom of the present invention can be used as standard substance for the correlative study of bismuth series superconducting material, significant in optimization bismuth series superconducting material performance etc.

Accompanying drawing explanation

Fig. 1 is gained Ca of the present invention ₂pbO ₄the X-ray powder diffraction figure of powder and standard diagram,

Fig. 2 is gained Ca of the present invention ₂pbO ₄the scanning electron microscope (SEM) photograph of powder.

Embodiment

Embodiment: the present embodiment is basic embodiment.One pressed powder synthesis method prepares Ca ₂pbO ₄method, comprise the following steps:

Preparation: take 5.0g plumbous oxide or 7.5g lead nitrate pressed powder, 2.5 ~ 4.0g calcium oxide or 7.7 ~ 11.6g nitrocalcite pressed powder, fully grind in agate mortar, two kinds of materials are mixed completely.Mixed powder is placed in compacting in corundum crucible, crucible is placed in 600 ~ 800 DEG C of high-temperature roastings in retort furnace, soaking time 24h.

Purifying: products obtained therefrom is ground, sieves, with washing soln supersound washing 3 ~ 8 times, each 2 ~ 10min, then use deionized water wash 5 times, and filter, dry.Adopt filtration under diminished pressure to carry out solid-liquid separation, after oven dry, obtain pure Ca ₂pbO ₄powder.

Table 1 experimental result

thisinvent the Ca prepared ₂pbO ₄for off-white powder, the result of X-ray powder diffraction (Fig. 1) can obtain, and is Ca in the product prepared ₂pbO ₄phase, scanning electron microscope (SEM) photograph (Fig. 2) shows gained Ca ₂pbO ₄for the cubes of rule.Detected by chemical method, Ca in product ₂pbO ₄percentage composition reach as high as more than 99%, purity is higher.Stable in products obtained therefrom air, kept dry.

The above is only the preferred embodiment for the present invention; it should be pointed out that the member of ordinary skill for the art, under the prerequisite not departing from the technology of the present invention principle; can also make some improvement and modification, these improve and modification also should be considered as protection scope of the present invention.

Claims (1)

1. prepare Ca with solid-phase synthesis for one kind ₂pbO ₄the method of powder, is characterized in that, the method comprises the following steps:

(1) a kind of and lead nitrate in calcium oxide or nitrocalcite or a kind of the formed pressed powder in plumbous oxide, is taken, fully grind in agate mortar, two kinds of materials are mixed completely, wherein, calcium and lead element stoichiometric ratio are between 2:1 ~ 3:1;

(2) mixed powder, by step 1 obtained is placed in compacting in corundum crucible, then crucible is placed in high-temperature roasting in retort furnace, and reaction generates Ca ₂pbO ₄, wherein, temperature controls at 600 ~ 800 DEG C, time 24h;

(3) Ca, step 2 obtained ₂pbO ₄grinding, sieve, with washings ultrasonic cleaning 3 ~ 8 times, each 2 ~ 10min also filters to isolate product, then uses deionized water wash 3 ~ 8 times, and filtration under diminished pressure carries out solid-liquid separation, and drying obtains high-purity C a ₂pbO ₄powder, wherein, is ground to Ca ₂pbO ₄granularity is 60 ~ 120 microns, and described washings is the one in 0.5% ~ 3% ammonium chloride solution, pH=4 ~ 5 hydrochloric acid soln, pH=4 ~ 5 sulphuric acid soln, pH=4 ~ 5 acetum.