Granular material, granular material manufacturing method, three-dimensional laminated and shaped mold manufacturing apparatus, and three-dimensional laminated and shaped mold manufacturing method

A granular material for use in three-dimensional laminated mold shaping, comprising:

• (a) a mixed or coated material comprising a refractory granular raw material mixed with or coated with a first acid that, when printed with an organic binder, serves as a catalyst to activate and harden the organic binder to bind the granular material;
• and
• (b) a hardening accelerator,
• wherein the hardening accelerator is a second material that, when the mixed or coated material is printed with the organic binder, (i) undergoes a metathesis reaction to generate a second acid that catalyzes a hardening reaction of the organic binder;
• (ii) causes a hydration reaction with water generated during the hardening reaction to increase a rate of the hardening reaction, and (iii) absorbs moisture;
• wherein the first acid contains at least one of sulfuric acid, phosphoric acid, and a sulfonic acid, and wherein the sulfonic acid contains at least one of p-toluenesulfonic acid, xylene sulfonic acid, benzene sulfonic acid, and methane sulfonic acid.