On what Biblical basis did Mormon prophet Joseph Smith teach that the "Ancient of Days" at Daniel 7:22 is the first man Adam?

There isn't much more scriptural basis for the above.

Joseph Smith was a prophet, seer, and revelator.¹ Daniel was a prophet as well. Both were capable of receiving revelation from God about the future.

• prophet

A person who has been called by and speaks for God. As a messenger of God, a prophet receives commandments, prophecies, and revelations from God. ... On occasion, prophets may be inspired to foretell the future for the benefit of mankind.

• seer

A person authorized of God to see with spiritual eyes things that God has hidden from the world. ... A seer knows the past, present, and future.

• revelator (one who receives revelation)

Communication from God to His children on earth. Revelation may come through the Light of Christ and the Holy Ghost by way of inspiration, visions, dreams, or visits by angels.

Two additional scriptures do come to mind.

D&C 107:53-57 tells not only of a similar event (Adam meeting in Adam-ondi-Ahman with other priesthood holders before the Lord came), but also of recording/fortelling things to come (in book of Enoch, which is lost scripture)

53 Three years previous to the death of Adam, he called Seth, Enos, Cainan, Mahalaleel, Jared, Enoch, and Methuselah, who were all high priests, with the residue of his posterity who were righteous, into the valley of Adam-ondi-Ahman, and there bestowed upon them his last blessing.

54 And the Lord appeared unto them, and they rose up and blessed Adam, and called him Michael, the prince, the archangel.

55 And the Lord administered comfort unto Adam, and said unto him: I have set thee to be at the head; a multitude of nations shall come of thee, and thou art a prince over them forever.

56 And Adam stood up in the midst of the congregation; and, notwithstanding he was bowed down with age, being full of the Holy Ghost, predicted whatsoever should befall his posterity unto the latest generation.

57 These things were all written in the book of Enoch, and are to be testified of in due time.

Matt 25:14-30

It is sufficient to know that it is a gathering of the Priesthood of God from the beginning of this earth down to the present, in which reports will be made and all who have been given dispensations (talents) will declare their keys and ministry and make report of their stewardship according to the parable.²

Daniel 7:9-13

9 ¶ I beheld till the thrones were cast down, and the Ancient of days did sit, whose garment was white as snow, and the hair of his head like the pure wool: his throne was like the fiery flame, and his wheels as burning fire.

10 A fiery stream issued and came forth from before him: thousand thousands ministered unto him, and ten thousand times ten thousand stood before him: the judgment was set, and the books were opened.

11 I beheld then because of the voice of the great words which the horn spake: I beheld even till the beast was slain, and his body destroyed, and given to the burning flame.

12 As concerning the rest of the beasts, they had their dominion taken away: yet their lives were prolonged for a season and time.

13 I saw in the night visions, and, behold, one like the Son of man came with the clouds of heaven, and came to the Ancient of days, and they brought him near before him.

14 And there was given him dominion, and glory, and a kingdom, that all people, nations, and languages, should serve him: his dominion is an everlasting dominion, which shall not pass away, and his kingdom that which shall not be destroyed.

Son of Man is referring to Jesus Christ.

Ancient of Days is referring to Adam. There is no physical description of Adam to compare against and living 930 years (Gen 5:5) would probably bring about a few white hairs.

Further explanation from The Man Adam² article

the Prophet Joseph Smith said: “Daniel in his seventh chapter speaks of the Ancient of Days; he means the oldest man, our Father Adam, Michael, he will call his children together and hold a council with them to prepare them for the coming of the Son of Man. He (Adam) is the father of the human family, and presides over the spirits of all men, and all that have had the keys must stand before him in this grand council. … The Son of Man stands before him, and there is given him glory and dominion. Adam delivers up his stewardship to Christ, that which was delivered to him as holding the keys of the universe, but retains his standing as head of the human family.”

President Joseph Fielding Smith offered the following explanation: “This gathering of the children of Adam, where the thousands, and the tens of thousands are assembled in the judgment, will be one of the greatest events this troubled earth has ever seen. At this conference, or council, all who have held keys of dispensations will render a report of their stewardship. Adam will do likewise, and then he will surrender to Christ all authority. Then Adam will be confirmed in his calling as the prince over his posterity and will be officially installed and crowned eternally in this presiding calling. Then Christ will be received as King of kings, and Lord of lords. We do not know how long a time this gathering will be in session, or how many sessions may be held at this grand council. It is sufficient to know that it is a gathering of the Priesthood of God from the beginning of this earth down to the present, in which reports will be made and all who have been given dispensations (talents) will declare their keys and ministry and make report of their stewardship according to the parable.

LDS rely on modern revelation of the interpretation for Daniel 7 on who the ancient of days is.

_{1 Prophet, Seer, and Revelator}

_{2 The Man Adam}

_{emphasis mine}

No biblical basis at all. The basis is revelation to him. So, the answer to "who has visions of Adam being the "Ancient of Days" and calling for a council meeting in the state of Missouri?" is Joseph Smith. Or, if you accept the interpretation, then of course Daniel, although Daniel of course has no knowledge of a state of Missouri.

D&C 116

1 Spring Hill is named by the Lord Adam-ondi-Ahman, because, said he, it is the place where Adam shall come to visit his people, or the Ancient of Days shall sit, as spoken of by Daniel the prophet.

Note that although this isn't explicitely coming from a context of the Bible translation work he was doing, it might be related. During that time, he pondered a lot over many scripture and received insights as to how to interpret them.

In D&C 107, which came in 1835, three years before D&C 116, Adam-ondi-Ahman got introduced as the place where Adam gave his final blessing to his posterity, similarly to how Jacob did in the Bible. However this did not, as far as I can see, include any reference to Daniel or a later meeting there with a resurrected Adam. Or even where this place exactly was. 1838, while close to Spring Hill, D&C 116 came and identified the place, as well as include this interpretation which connects Adam and the Ancient of Days.

I am not sure what it is you have against this interpretation (other than the fact that it comes "out of nowhere" as a revelation to Joseph Smith):

If the Ancient of Days is Adam, then what we see in Daniel 7 is Jesus returning (one like the Son of man), and Adam (the Ancient of Days) returning the dominion that was given him in Genesis to Jesus.

https://www.churchofjesuschrist.org/study/ensign/1994/01/the-man-adam?lang=eng

Of this council, a meeting that will be a preliminary appearance of the Savior (prior to his coming in glory), the Prophet Joseph Smith said: “Daniel in his seventh chapter speaks of the Ancient of Days; he means the oldest man, our Father Adam, Michael, he will call his children together and hold a council with them to prepare them for the coming of the Son of Man. He (Adam) is the father of the human family, and presides over the spirits of all men, and all that have had the keys must stand before him in this grand council. … The Son of Man stands before him, and there is given him glory and dominion. Adam delivers up his stewardship to Christ, that which was delivered to him as holding the keys of the universe, but retains his standing as head of the human family.”

President Joseph Fielding Smith offered the following explanation: “This gathering of the children of Adam, where the thousands, and the tens of thousands are assembled in the judgment, will be one of the greatest events this troubled earth has ever seen. At this conference, or council, all who have held keys of dispensations will render a report of their stewardship. Adam will do likewise, and then he will surrender to Christ all authority. Then Adam will be confirmed in his calling as the prince over his posterity and will be officially installed and crowned eternally in this presiding calling. Then Christ will be received as King of kings, and Lord of lords.