[LETTERHEAD OF GOLENBOCK, EISEMAN, ASSOR & BELL]


                              December 17 , 1998



Philipp Brothers Chemicals, Inc.
One Parker Plaza
Fort Lee, N.J. 07024

                  Re:  Philipp Brothers Chemicals, Inc. Registration Statement 
                       on Form S-4

Ladies and Gentlemen:

                  We have acted as counsel to Philipp Brothers Chemicals,
Inc., a New York corporation (the "Company"), and the Designated Guarantors
(as hereinafter defined), in connection with the public offering of
$100,000,000 aggregate principal amount of 9 7/8% Senior Subordinated Notes
due 2008 (the "New Notes") of the Company, which will be guaranteed, on a
senior subordinated basis pursuant to the guarantees (the "Guarantees" and,
together with the New Notes, the "New Securities") by Phibro-Tech, Inc., a
Delaware corporation, Prince Agriproducts, Inc., a Delaware corporation, MRT
Management Corp., a Delaware corporation, Mineral Resource Technologies,
L.L.C. ("MRT"), a Delaware limited liability company, Koffolk, Inc., a
Delaware corporation, C.P. Chemicals, Inc., a New Jersey corporation,
Phibrochem, Inc., a New Jersey corporation, Phibro Chemicals, Inc., a New York
corporation, The Prince Manufacturing Company, an Illinois corporation, The
Prince Manufacturing Company, a Pennsylvania corporation, and Western
Magnesium Corp., a California corporation (collectively, the "Guarantors").
The eight Guarantors that are incorporated or formed under the laws of the
States of New York, Delaware or New Jersey are collectively referred to as the
"Designated Guarantors." The New Securities are to be issued pursuant to an
exchange offer (the "Exchange Offer") in exchange for a like principal amount
of the issued and outstanding 9 7/8% Senior Subordinated Notes due 2008 of the
Company (the "Old Securities") under an Indenture dated as of June 11, 1998
(the "Indenture"), by and among the Company, the Guarantors and The Chase
Manhattan Bank, as trustee (the "Trustee"), as contemplated by the
Registration Rights Agreement dated June 11, 1998 (the "Registration Rights
Agreement"), by and among the Company, the Guarantors and Schroder & Co. Inc.

                                                




Philipp Brothers Chemicals, Inc.
December 17, 1998
Page 2


                  This opinion is being furnished to you in accordance with
the requirements of Item 601(b)(5) of Regulation S-K under the Securities Act
of 1933, as amended (the "Act"), in connection with the filing of the
Registration Statement (as hereinafter defined) and for no other purpose.

                  In connection with this opinion, we have examined originals
or copies, certified or otherwise identified to our satisfaction, of (i) the
Registration Statement on Form S-4 (File No. 333-64641) as filed with the
Securities and Exchange Commission (the "Commission") on September 29, 1998
under the Act, and Amendment No.1 thereto as filed with the Commission on
November 23, 1998, Amendment No. 2 thereto as filed with the Commission on
December 14, 1998, and Amendment No. 3 thereto filed with the Commission on
December 17, 1998 (such Registration Statement, as so amended, being
hereinafter referred to as the "Registration Statement"); (ii) an executed
copy of the Registration Rights Agreement; (iii) an executed copy of the
Indenture; (iv) the Certificate of Incorporation of the Company, the
Certificate of Formation of MRT, and the Certificate of Incorporation of each
of the other Designated Guarantors, each as amended to date; (v) the By-Laws
of the Company, the Limited Liability Company Agreement of MRT, and the
By-Laws of each of the other Designated Guarantors, each as amended to date;
(vi) Certificates issued by the Secretary of State of the States of New York,
Delaware and New Jersey, certifying the existence of the Company and each of
the Designated Guarantors and its respective authority to transact business in
its state of incorporation or formation; (vii) certain resolutions adopted by
the Board of Directors and shareholders of the Company, relating to the
Exchange Offer, the issuance of the New Notes and the New Securities, the
Indenture and related matters, certified by the Secretary of the Company as
true and complete; (viii) certain resolutions adopted by the Board of
Directors and shareholders (or, in the case of MRT, the Managing Member) of
each of the Designated Guarantors relating to, among other things, the
issuance of the Guarantees by the Designated Guarantors, certified by the
Secretary of each of the applicable Designated Guarantors as true and
complete; (ix) the Form T-1 of the Trustee filed as an exhibit to the
Registration Statement; and (ix) the form of the New Notes (including the form
of Guarantees). We have also examined originals or copies, certified or
otherwise identified to our satisfaction, of such records of the Company and
the Designated Guarantors and such agreements, certificates of public
officials, certificates of officers or other representatives of the Company,
the Designated Guarantors and others, and such other documents, certificates
and records as we have deemed necessary or appropriate as a basis for the
opinions set forth herein.

                  In rendering these opinions we have assumed (i) the
genuineness of all signatures, the legal capacity of all natural persons, the
authenticity of all documents submitted to us as

                                                      




Philipp Brothers Chemicals, Inc.
December 17, 1998
Page 3


originals, the conformity to original documents of all documents submitted to
us as certified, conformed or photostatic copies or by electronic means and
the authenticity of the originals of such latter documents; (ii) that all
parties other than the Company and the Designated Guarantors have the power,
corporate or otherwise, to enter into and perform all obligations under all
documents we have examined in connection with these opinions (the "Examined
Documents"); (iii) that all the Examined Documents have been duly authorized
by all requisite action, corporate or other, and executed and delivered by,
and each of them constitutes the legally valid and binding obligation of, such
other parties, as applicable, enforceable against such other parties in
accordance with their respective terms; and (iv) that the resolutions of the
Board of Directors and shareholders (and, in the case of MRT, the Managing
Member) of the Company and the Designated Guarantors in connection with the
Purchase Agreement dated June 5, 1998 between the Company and Schroder & Co.
Inc. and the sale of the Old Securities have not been rescinded and revoked.
We have also assumed (i) that the execution, delivery and performance of the
Guarantees and the Indenture by each of the Guarantors incorporated under the
laws of Pennsylvania, Illinois or California will not violate any provisions
of the laws of such state, (ii) the validity, binding effect and
enforceability of the Indenture and the Guarantees of the Guarantors
incorporated under the laws of Pennsylvania, Illinois or California under the
laws of such states, and (iii) that the laws of such jurisdictions would not
affect any of the conclusions stated herein. As to any fact material to the
opinions expressed herein which we have not independently established or
verified, we have relied upon statements and representations of officers and
other representatives of the Company, the Guarantors and others. In addition,
we have assumed that there will be no changes in applicable law between the
date of this opinion and the date of issuance and delivery of the New
Securities.

                  Members of our firm are admitted to the bar in the State of
New York and we express no opinion with regard to any matter which may be
governed by any law other than the federal law of the United States of
America, the laws of the State of New York and, to the extent necessary to
render this opinion, the Delaware corporate law and the New Jersey corporate
law.

                  Based upon and subject to the foregoing and the limitations,
assumptions, qualifications and exceptions set forth herein, we are of the
opinion that the New Securities have been duly authorized by the Company and
the Designated Guarantors, and when (i) the Registration Statement becomes
effective under the Act and the Indenture has been qualified under the Trust
Indenture Act of 1939, as amended, and (ii) the New Securities have been duly
executed and authenticated in accordance with the terms of the Indenture and
have been delivered upon consummation of the Exchange Offer against receipt of
Old Securities 
                                                      




Philipp Brothers Chemicals, Inc.
December 17, 1998
Page 4

surrendered in exchange therefor in accordance with the terms of the Exchange
Offer, the New Securities will constitute valid and binding obligations of the
Company and each of the Designated Guarantors, enforceable against the Company
and each of the Designated Guarantors in accordance with their terms.

                  The opinion set forth above is qualified as follows:

                  A. The validity and enforceability of obligations, and the
availability of rights and remedies, under the Indenture and under the
Guarantees, are subject to and may be limited or affected by (i) bankruptcy,
insolvency, reorganization, moratorium or similar laws now or hereafter in
effect affecting creditors' rights generally (including, without limitation,
Section 548 of the United States Bankruptcy Code, state fraudulent transfer
laws and other similar laws relating to fraud on creditors), and (ii) general
principles of equity, regardless of whether such validity or enforceability of
obligations or availability of rights and remedies is considered in a
proceeding in equity or at law.

                  B. The validity and enforceability of obligations, and the
availability of rights and remedies, under the Indenture and the Guarantees,
may be further limited by other laws and judicial decisions with respect to or
affecting remedial or procedural provisions contained in such documents, but
in our judgment and subject to the other qualifications set forth in this
letter, such other laws and judicial decisions do not render the Indenture
invalid as a whole or substantially interfere with realization of the
principal benefits intended to be provided thereby.

                  C. The validity and enforceability of obligations, and the
availability of rights and remedies, under the Indenture, including the
Guarantees under the Indenture, may be further limited by other laws and
judicial decisions with respect to the enforceability of any waiver granted
under Section 6.04 of the Indenture.

                  We hereby consent to the filing of this opinion with the
Commission as an exhibit to the Registration Statement. We also consent to the
reference to our firm under the caption "Legal Matters" in the Registration
Statement. In giving this consent, we do not thereby admit that we are
included in the category of persons whose consent is required under Section 7
of the Act or the rules and regulations of the Commission.



                                      Very truly yours,

                                      /s/ Golenbock, Eiseman, Assor & Bell