English name Acid Red : Trisodium 3-hydroxy-4-(4-sulfonato-1-naphthylazo)-2,7-naphthalenedisulfonate
Product name Amaranth Red; 1-(4-sulfonato-1-naphthylazo)-2-hydroxy-3, 6-Naphthalenedisulfonic acid trisodium salt
Molecular formula C20H11N2Na3O10S3
Molecular weight 604.47
CAS Registry Number 915-67-3
Amaranthine Red can be prepared in two ways
One of them is the extraction of the natural red coloring pigment from amaranth
The process is as follows. Amaranth - Cleaning - Chopping - Leaching - Pressing - Filtration - Concentration - Dry Huan - Finished product. To pay attention to the following aspects
(1) raw material selection:
The raw materials used should be selected pigment containing halo higher varieties to ensure product quality, for the degradation of the varieties should not be used, the best
with the raw materials of the mid-growth.
(2) trimming, cleaning: from dry raw materials often entrapped in mud and sand and impurities, must be trimmed and washed before dipping.
(3) chopping:
In order to increase the solid-liquid two-phase contact area, in order to facilitate the improvement of the leaching rate, therefore, it is necessary to have been washed before the leaching of the raw
material chopped fine, but can not be chopped too fine, otherwise it will increase the separation workload of the post-process.
(4) leaching:
Use appropriate amount of water as leaching agent, leaching at a certain temperature.
(5) Pressing and filtration:
The leachate obtained above is loaded into cloth bags or filters for pressurized filtration, and the filtrate is sent to the concentration process. The resultant filtrate contains calcium, phosphorus, iron and fiber, and can be used as animal feed.
(6) Concentration:
The filtrate is concentrated to a certain concentration with a falling film evaporator.
(7}Spray drying:
The concentrate is sent to the centrifugal spray dryer in the spray in the dry (i.e., water content of about 1.4% of the rose violet-red powdery pigment.
Another synthetic method
Method: p-aminonaphthalenesulfonic acid diazotization and 2-naphthol-3,6-disulfonic acid coupling, refined by salinization.
No specific reaction process has been found
.