ACO Amcol International Corp.

AMCOL International Corporation 1987 Non-Qualified Stock Option Plan

AMCOL International Corporation 1993 Stock Plan

AMCOL International Corporation 1998 Stock Plan

AMCOL International Corporation 2006 Stock Plan

AMCOL International Corporation 2010 Stock Plan

(Full title of the plan)

Thomas J. Meek, Esq.

Senior Vice President, General Counsel and Secretary

AMCOL International Corporation

c/o Minerals Technologies Inc.

622 Third Avenue

New York, New York 10017-6707

(Name and address of agent for service)

(212) 878-1800

(Telephone number, including area code, of agent for service)

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See definition of “accelerated filer,” “large accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act: (Check one):

DEREGISTRATION OF SECURITIES

These post-effective amendments relate to the following Registration Statements of AMCOL International Corporation (the “Company”) on Form S-8 (collectively, the “Registration Statements”):

On March 10, 2014, the Company entered into an Agreement and Plan of Merger (the “Merger Agreement”) by and among the Company, Minerals Technologies Inc., a Delaware corporation (“MTI”) and MA Acquisition Inc., a Delaware corporation and a wholly owned subsidiary of MTI (“Merger Sub”). On May 9, 2014, pursuant to the Merger Agreement, Merger Sub was merged with and into the Company (the “Merger”), with the Company surviving the Merger as a wholly-owned subsidiary of MTI. At the effective time of the Merger, each share of Company Common Stock issued and outstanding immediately prior to the effective time, other than (i) shares held by the Company as treasury stock or owned by MTI or Merger Sub, all of which were canceled, and (ii) shares owned by stockholders of the Company who or which were entitled to demand, and who properly demanded, appraisal rights pursuant to Section 262 of the DGCL, was converted into the right to receive an amount in cash equal to $45.75 per share, net to the seller in cash, without interest and less any applicable withholding taxes.

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In connection with the Merger, the offerings of securities pursuant to the Registration Statements have been terminated. In accordance with undertakings made by the Company in the Registration Statements to remove from registration, by means of post-effective amendments, any of the securities registered pursuant to the Registration Statements that remain unsold at the termination of the offerings, the Company hereby removes from registration all Common Stock registered under the Registration Statements but not sold under the Registration Statements as of the filing date of these post-effective amendments.

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