PATENT CLAIM ANALYSIS

Application Number: 15760851
Application Type: Utility
Filing Date: 2018-03
Publication Date: 2018-09
Patent Classification: ["423", "172000"]

Abstract:
Provided is a method for producing phosphoric acid and at the same time obtaining alpha-hemihydrate gypsum including: adding a phosphate rock powder and a part of dilute sulfuric acid into an extraction tank, carrying out an extraction reaction on same, separating a clear liquid from the obtained mixed slurry, sending the clear liquid, as a finished product phosphoric acid, into an acid storeroom, and transferring a separated solid, together with the rest mixed slurry, into a crystal transformation tank; and adding sulfuric acid and a crystal transformation agent into the crystal transformation tank, carrying out a crystal transformation reaction for 1.5-7.5 h at 60° C.-130° C., and solid-liquid separating the obtained mixed acid slurry, wherein the solid can be dried into a gypsum powder, or may be not subjected to a drying step and made into gypsum products such as gypsum boards, gypsum building blocks and gypsum members by directly adding water.

Claim (Index 17):
The method for producing wet-process phosphoric acid and at the same time obtaining alpha-hemihydrate gypsum as by-product according to  claim 8 , comprising the following steps:\n (1) adding phosphate rock powder and diluted sulfuric acid with a mass concentration of 20% into an extraction tank according to a solid-liquid mass ratio of 1:4, wherein the fineness of the phosphate rock powder is 100-mesh and the phosphorus pentoxide content in the phosphate rock is 32%; performing an extraction reaction for 30 minutes under controlling the temperature of the extraction tank at 80\u00b0 C. under stirring to obtain a mixed slurry A; (2) taking a fraction of \u2159 volume of the mixed slurry A obtained in step S1) and performing a solid and liquid separation to obtain a supernatant B and a solid C; transferring the supernatant B to an acid storage as final phosphoric acid and transferring the solid C to a crystal transformation tank together with the rest mixed slurry; (3) adding diluted sulfuric acid with a mass concentration of 20% to the crystal transformation tank; controlling the liquid-solid mass ratio of mixed acid solution after decalcification and slag slurry at 6:1 to obtain a mixed slurry, wherein the liquid phosphoric acid in terms of P 2 O 5  is 20% by mass fraction of the mixed acid and the sulfuric acid in terms of H 2 SO 4  is 9% by mass fraction of the mixed acid; then, adding crystal transformation agents: iron sulfate accounted for 0.23% of the mass of the mixed slurry, sodium citrate accounted for 0.12% of the mass of the mixed slurry, and sodium lignosulfonate accounted for 0.08% of the mass of the mixed slurry; performing crystal transformation reaction for 3 h under maintaining the temperature of crystal transformation tank is maintained at 110\u00b0 C. to obtain a mixed acid slurry D; (4) separating solid and liquid in the mixed acid slurry D obtained in step (3) to obtain a solid E and a filtrate F; washing the solid E with 85\u00b0 C. hot water to obtain a washing liquid H and a solid G; and drying the solid G by a blow-dryer at a drying temperature of 110\u00b0 C. to obtain an alpha-hemihydrate gypsum; (5) introducing the filtrate F in step (4) into the extraction tank of step (1) to continue the extraction of phosphate rock powder; introducing the washing liquid H into a sulfuric acid diluting tank to dilute concentrated sulfuric acid, which is used for the extraction process of step (1) and the crystal transformation process of step (3); introducing vapor generated during the dilution process into the crystal transformation tank to provide heat for reaction.

Metadata:
- Claim Count in Document: 38.0
- Percentile: 90.0
- Lexical Diversity: 1.97647
- Patent Class: 423.0
- Transitional Phrase Type: open
- Component Type: 1
- Foreign Priority: True
- Related Applications: ['15760822', '10362845', '16312906', '13055891', '15300822']

Analysis Scores:
- 35 USC 101 Eligibility (BERT): 0.7897374712737372
- 35 USC 102 Novelty (BERT): 0.5804223477273128
- Combined Prediction Score: 0.7688059589190948
- Mean Citation Score: 335.13012600000013
- Max Citation Score: 513.0573
- Similarity Product: 404.9550385632098

Labels:
- Claim Label 101: 1
- Claim Label 102: 1
- Claim Label 103: 1
- Claim Label 112: 1
- Combined Label: 1
- Label 101 Adjusted: 1

Dataset: test