Power of Attorney

Know all by these presents, that the undersigned hereby constitutes and
appoints Roger Jackson, General Counsel of KMG Chemicals, Inc. (the
"Company"), the undersigned's true and lawful attorney-in-fact to:

(1)   execute for and on behalf of the undersigned, in the undersigned's
capacity as an officer of the Company, Forms 3, 4 and 5 in accordance with
Section 16(a) of the Securities Exchange Act of 1934, as amended, and the
rules thereunder;

(2)   do and perform any and all acts for and on behalf of the undersigned
which may be necessary or desirable to complete and execute any such Form 3,
4 or 5 and timely file such form with the United States Securities and
Exchange Commission and any stock exchange or similar authority; and

(3)   take any other action or any type whatsoever in connection with the
foregoing which, in the opinion of such attorney-in-fact, may be of benefit
to, in the best interest of, or legally required by, the undersigned, it
being understood that the documents executed by such attorney-in-fact on
behalf of the undersigned pursuant to this Power of Attorney shall be in
such form and shall contain such terms and conditions as such attorney-in-fact
may approve in such attorney-in-fact's discretion.

The undersigned hereby grants to each attorney-in-fact full power and authority
to do and perform any and every act and thing whatsoever requisite, necessary or
proper to be done in the exercise of any of the rights and powers herein
granted, as fully to all intents and purposes as the undersigned might or
could do if personally present, with full power of substitution or
revocation, hereby ratifying and confirming all that such attorney-in-fact,
or such attorney-in-fact's substitute or substitutes, shall lawfully do or
cause to be done by virtue of this power of attorney and the rights and powers
herein granted. The undersigned acknowledges that the foregoing
attorney-in-fact,in serving in such capacity at the request of the undersigned,
are not assuming, nor is the Company assuming any of the undersigned's
responsibilities to comply with Section 16 of the Securities Exchange
Act of 1934.

This Power of Attorney shall remain in full force and effect until the
undersigned is no longer required to file Forms 3, 4 and 5 with respect to
the undersigned's holdings of and transaction in securities issued by the
Company, unless earlier revoked by the undersigned in a signed writing
delivered to the foregoing attorneys-in fact.

IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be
executed as of the 14th day of August, 2017.

/s/ Margaret Montana
_________________
Margaret C. Montana