Production of chalk from oyster shells and eggshells /
by Ma. Jeanina Lazaro, Jed Lemuel Vicedo, and Arnel Feraer.
- Indang, Cavite : Cavite State University- Main Campus, 2009.
- xiv, 38 pages : illustrations ; 28 cm.
Research Study (Science High School) Cavite State University
Includes bibliographical references.
FERAER, ARNEL R.; LAZARO, MARIA JEANINA B.; VICEDO, JED LEMUEL R; Production of Chalk From Oyster Shells And Eggshells. Applied Research III Science High School, College of Education, Cavite State University, Indang, Cavite. April 2009. Adviser: Prof. Cynthia A. Corpuz. The study entitled "Production of Chalk from Oyster Shells and Eggshells" was conducted at Tambo Munti Kulit, Indang, Cavite and Cavite State University, College of Arts and Sciences, Department of Physical Science to produce chalks from oyster shells and eggshells. It also aimed to 1) determine the physical properties of the chalk produced from oyster shells and eggshells, and 2) determine which treatment will produce the best quality of chalk. The researchers used the following treatments in the conduct of their study: To = commercial chalk; T1 = 10 g of oyster shells; T2 = 7 g of oyster shells + 3 g eggshells; T3 = 5 g of oyster shells + 5 g eggshells; T4 = 3 g of oyster shells + 7 g eggshells, and; T5 = 10 g eggshells each having a constant weight of 5 g Plaster of Paris. The oyster shell and eggshell were cleaned and pounded to the most possible smallest size using a grinder and the mortar and pestle. The shells were mixed with Plaster of Paris and water and were cooked for five minutes or until the shells become hot enough for the binder to function effectively. The solution were placed in a molder and air dried for three days. To further dry the chalks, the researchers used an oven. The chalks were evaluated by fifty respondents based on its texture, brittleness, compactness, hardness, adherence, erasability, and general acceptability with a sensory evaluation sheet.