金瓜石礦區骨材性質之研究

Aggregate characteristics of rocks from the Chinkuashih Mine

黃琨哲(Kun-Che Huang)

指導教授 ： 余炳盛

國立臺北科技大學/工程學院/材料科學與工程研究所/碩士(2007年)

摘要

金瓜石金銅礦仍具有高的開發潛能，若重新開採時，其大量圍岩及廢石應可提供骨材應用，唯此區的岩石多因熱水作用而受到不同程度的矽化、黏土化、綠泥石化等換質作用，其骨材性質恐怕與新鮮岩石不同，故本研究係針對這些剝離後堆積在礦山附近的岩石或礦體外緣的廢石進行各項骨材性質試驗，以瞭解這些經過熱水換質作用後之岩石其性質是否滿足營建工程用骨材之需求。
本研究於金瓜石各種換質作用分佈區域採取矽化、黏土化、綠泥石化及新鮮安山岩與矽化、黏土化及新鮮砂岩樣品各兩件，經由XRD鑑定及XRF成分分析確認樣品性質後，依照中華民國國家標準 (CNS) 進行各項骨材基本性質試驗及美國材料與試驗協會（ASTM）之化學法及水泥砂漿棒法進行鹼-骨材反應試驗。
試驗結果顯示黏土化安山岩及砂岩富含大量黏土，性質軟弱，不適為各種骨材試驗，故歸類為劣質骨材。綠泥石化及新鮮安山岩在XRF成分分析上所表現之性質相近，兩者間變化不大，骨材試驗兩者皆符合規範要求，其中綠泥石化安山岩受熱水作用影響，在骨材堅硬程度及強度性質上要比新鮮安山岩來得好一些。矽化安山岩及砂岩經強度及耐久性試驗結果顯示其性質非常堅硬，但矽化安山岩由於受過熱水換質作用，使其岩石變為多孔性，比重2.35左右，雖不符合CNS之要求，但其質輕強度高之特性，與一般常用骨材不同，需進一步探討其工程之適用性。新鮮砂岩試體方面，7A試體為一軟質砂岩，岩體膠結差、質地軟弱易碎，導致各項試驗均未達標準。

關鍵字

金瓜石 ； 換質作用 ； 骨材性質

並列摘要

There are still highly exploitable potential in the Chinkuashih gold-copper mine. When mining again, a large number of wall rock and waste fill can be used for aggregates. But rocks of this district may be alternated by hydrothermal solutions including a large variety of silicification, argillic and propyllitic alteration. The characteristics of alternated rocks are probably different from fresh rocks. Therefore, a series of tests were conducted in this study in order to understand the aggregate properties of wall rocks and waste fills in this area and determine these alternated rocks for the requirements of building engineering.
Two samples of each four types of dacite, including silisified, argillic, propyllitic and fresh and three types of sandstone, including silisified, argillic and fresh, are collected in Chinkuashih distribution, respectively. After confirming the samples with XRD mineral examination and XRF composition analysis, the aggregate experiments according to CNS and ASTM codes include several aggregate property tests and alkali-aggregate reaction test are conducted.
The results show that the argillic dacite and sandstone rich in a large amount of clay mineral and can’t be test for various kinds of aggregate experiments, so classified as bad-ranking aggregate. The decites of propyllitic alteration and fresh are similar in XRF composition analysis and both accord with requirements of CNS codes. Propyllitic decite is better in strength as a result of undergoing hydrothermal alteration. Silisified dacite and sandstone are very hard by the strength and durable tests. Nevertheless, silisified dacite has been altered by hydrothermal solutions to be generally more porous than unaltered rocks. The specific gravity of silisified dacite is about 2.35 g/cm2. Although it does not accord with the requirement for CNS, the characteristics of lightweight and high strength of silisified dacite are different from common aggregates. It is need to probe into the applicability of its civil engineering further. The sample 7 A of Fresh sandstone is a kind of weak sandstone. The rock matrix cementation is bad and it is so fragile that the results of tests havn’t reached the standard.

並列關鍵字

Chinkuashih ； Hydrothermal alteration ； Aggregate characteristics

參考文獻

[3] 方建能、余炳盛，金瓜石-九份金銅礦導覽，台灣省立博物館，1995，304頁。

[7] Huang, C.K. “Factors controlling the gold-copper deposits of the Chinkuashih mine, Taiwan.” Acta Geological Taiwanica, no.10, 1963, pp.1-9.

[19] Wang, Y., Munetake, S., Chen, C.H., “Fluid inclusion studies of the Chinkuashih high-sulfidation gold–copper deposits in Taiwan,” Chemical Geology, vol.154, 1999,pp.155-167.

[21] Folinsbee, R.E., Kirkland, K., Nekolaichuk, A. and Smejkal, V. “Chinkuashih-a gold-pyrite-enargite-barite hydrothermal deposit in Taiwan.” Geol. Soc. Am. Mem, no.135, 1972, pp.323-335.

[26] A. M. Bateman, Economic mineral deposits, New York : J. Wiley, 1955, 916 p.