Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Process for preparing ammonium bichromate

A technology of ammonium dichromate and production method, applied in chromate/dichromate and other directions, can solve problems such as pollution and high cost, and achieve the effects of simple process, easy availability of raw materials and low cost

Inactive Publication Date: 2003-02-19
刘昌见
View PDF1 Cites 3 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0010] The purpose of the invention is to solve the problems of high cost and serious pollution in the current ammonium dichromate production process, and research and develop a clean process with simple production process, low cost and no pollution

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Process for preparing ammonium bichromate
  • Process for preparing ammonium bichromate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] In a four-necked flask that agitator and thermometer are installed, adding concentration is 280g of sodium chromate aqueous solution 280g (containing Na 2 CrO 4 98.0g, 0.605mol), add ammonium carbonate 96g (1.22mol) again, stir 1 hour at 45 ℃, filter, the sodium bicarbonate precipitation washes three times with 60mol moisture, and washing liquid merges in the mother liquor (I), obtains mother liquor ( 1) about 260ml, the precipitate is calcined at 160°C for 1 hour to obtain soda ash Na 2 CO 3 53g, containing 3% by weight of sodium chromate (which can be directly returned to the chromite roasting unit). In addition, the HCO in the mother liquor (I) was measured 3 - The concentration is about 2.85M, which is HCO 3 -The total content of 0.74mol. Pass into 20g NH in the mother liquor (I) 3 (1.18mol)(NH 3 / HCO 3 - = 1.5 mol / mol). Cool to 16°C to obtain 22.8g of ammonium chromate crystals, dry at 110°C for 2 hours to obtain 19.0g of photographic grade ammonium d...

Embodiment 2

[0031] In a four-necked flask equipped with stirrer and thermometer, adding concentration is 39% by weight of sodium chromate aqueous solution 540g (containing Na 2 CrO 4 211g, 1.30mol), add ammonium bicarbonate 220g (2.78mol) again, stir 0.5 hour at 50 ℃, filter, the sodium bicarbonate precipitate washes three times with 120ml water, and washing liquid merges in the mother liquor (I), obtains mother liquor ( 1) about 500ml. The precipitate was calcined at 120°C for 2 hours to obtain soda ash Na 2 CO 3 155g, containing 8% by weight of sodium chromate (can be directly returned to the chromite roasting unit). In addition, the HCO in the mother liquor (I) was measured 3 - The concentration is 2.96M, i.e. the HCO of the mother liquor (I) 3 - The total content is 1.48mol. Feed 25g NH into the mother liquor 3 (1.47mol)(NH 4 / HCO 3 - =0.99 mol / mol). After cooling to 18°C, 45.6 g of ammonium chromate crystals were obtained, and after drying at 100°C for 2.5 hours, 37.8 ...

Embodiment 3

[0032] In a four-necked flask equipped with a stirrer and a thermometer, adding a concentration is 30% by weight of sodium chromate aqueous solution 300g (containing Na 2 CrO 4 90g, 0.556mol), add ammonium bicarbonate 80g (1.01mol) again, stir 1 hour at 30 ℃, filter, the sodium bicarbonate precipitation washes three times with 90ml water, and washing liquid merges in the mother liquor (I), obtains mother liquor ( 1) about 310ml. Calcining the precipitate at 190°C for 0.5 hours to obtain soda ash Na 2 CO 3 51g, which contains 4.5 weight of sodium chromate (can be directly returned to the chromite roasting unit). In addition, the HCO in the mother liquor (I) was measured 3 - The concentration is 2.27M, i.e. the HCO of the mother liquor (I) 3 - The total content is 0.70 mol. Feed 25g NH into the mother liquor 3 (1.47mol)(NH 4 / HCO 3 - = 2.1 mol / mol). After cooling to 13°C, 24.2 g of ammonium chromate crystals were obtained, and after drying at 80°C for 3 hours, 20....

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

A process for preparing ammonium bichromate includes replacement reaction between sodium (or potassium) chromate and ammonium hydrogen carbonate in solution, solid-liquid separation to remove dicarbonate deposit, absorbing ammonia by mother liquid to convert the bicarbonate to high-solubility carbonate, cooling to educe out ammonium chromate, solid-liquid separation to collect ammonium chromate crystal, and pyrolyzing. Its advantages are simple process and no environmental pollution.

Description

technical field [0001] The present invention relates to the production method of ammonium dichromate, more specifically, relate to carry out metathesis reaction in aqueous solution with alkali metal chromate and ammonium bicarbonate as raw material, then heat and decompose the generated ammonium chromate to produce dichromic acid ammonium method. Background technique [0002] Ammonium dichromate is an important product in the chromium salt industry, and is widely used in photography, fireworks, tanning and catalysts. Ammonium dichromate is generally prepared by metathesis reaction of sodium dichromate and ammonium chloride or ammonium sulfate. Its chemical reaction formula is as follows: [0003] <chemistry num="001"> <chem file="02129076_cml001.xml" / > < / chemistry> (1) [0004] <chemistry num="002"> <chem file="02129076_cml002.xml" / > < / chemistry> (2) [0005] However, these methods produce a large amount of by-products...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): C01G37/14
Inventor 刘昌见
Owner 刘昌见
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com