Low-CTE, low-puffing needle coke
AssigneeNippon Steel Chemical & Material Co., Ltd.
InventorKyohei Hada
Life of this patent
Estimating the term…
Abstract
To provide low CTE and low puffing needle coke more stably while dealing with changes in the properties of a feedstock. The low CTE and low puffing needle coke is obtained by mixing and coking a needle coke main feedstock of a coal tar-based heavy oil or petroleum-based heavy oil having a weak hydrogen donating property with a PDQI value expressed by equation (1) of less than 5.0, with a secondary feedstock having a strong hydrogen donating property with a PDQI value expressed by equation (1) of 5.0 or more, and calcining the obtained raw coke. [Equation (1)] PDQI=H %×10×(HNβ/H), wherein H % is a hydrogen amount (% by weight) obtained by elemental analysis, and HNβ/H is a ratio of β naphthenic hydrogen to total hydrogen measured by 1H-NMR.
Claims6
Low CTE and low puffing needle coke, having a CTE-related structure index (NCSIC) expressed by equation (2) of more than 25.0, and a puffing-related structure index (NCSIP) expressed by equation (3) of more than 5.0:
- NCSIC=((Lc/d002)+(open pore ratio))/(σ(θ)) [Equation (2)]
- wherein Lc represents a crystallite size, d002 represents an interplanar spacing, and σ (θ) represents a standard deviation of average orientational angle;
- NCSIP=(open pore amount/closed pore amount)+(HIT/1000)/EIT [Equation (3)]
- wherein HIT represents an indentation hardness and EIT represents an indentation elastic modulus.
Dependencies are inferred from the claim text.