Question

Ball clay is used mainly to impart in clay body.

• A. For porosity
• B. For plasticity
• C. For viscosity
• D. For reduce plasticity

Hint:

Logic Tip: Ball clay = Fine particles = High plasticity. It acts as the "glue" that makes short clay workable.

Answer 1

The Correct Option is B

Concept:
Ball clay is a highly plastic, fine-grained secondary clay. It is a critical ingredient in many ceramic recipes, particularly those requiring strong workability.

Step 1:
Ball clays are sedimentary clays that have been transported by water over long distances. During this transport, the clay particles are ground down to microscopic, plate-like sizes.

Step 2:
The extremely fine particle size gives ball clay a massive surface area. When mixed with water, these tiny flat particles slide easily against one another, creating intense cohesion and flexibility. This physical property is known as plasticity.

Step 3:
Primary clays (like Kaolin) fire beautiful and white but are "short" (non-plastic and hard to throw or mold). Potters add 10% to 30% ball clay to a recipe specifically to make the stiff kaolin workable and plastic.

Step 4:
Because ball clay's primary function in a recipe is to make the clay moldable and workable, the correct answer is plasticity. \[ \boxed{\text{(2) For plasticity}} \]