| 摘要 |
A method for making pencil leads without firing includes taking mixtures of graphite and MgO which are made of Mg salts with MgCl2 solutions, forming such mixtures into desired shapes (crayons or pencil leads) and hardening them at room temperatures. Colored pencil leads are produced by processing MgO with inorganic or organic colors together with slip additives and MgCl2 solutions into pressable pastes, and then forming them into leads or crayons for room temperature hardening. To increase breakage resistance, the resulting leads or crayons are encased in wood. The MgCl2 solutions are mixtures of Sorel's cement, and the slip additive is talcum.
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